2 * @brief Lightning memory-mapped database library
4 * A Btree-based database management library modeled loosely on the
5 * BerkeleyDB API, but much simplified.
8 * Copyright 2011-2016 Howard Chu, Symas Corp.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted only as authorized by the OpenLDAP
15 * A copy of this license is available in the file LICENSE in the
16 * top-level directory of the distribution or, alternatively, at
17 * <http://www.OpenLDAP.org/license.html>.
19 * This code is derived from btree.c written by Martin Hedenfalk.
21 * Copyright (c) 2009, 2010 Martin Hedenfalk <martin@bzero.se>
23 * Permission to use, copy, modify, and distribute this software for any
24 * purpose with or without fee is hereby granted, provided that the above
25 * copyright notice and this permission notice appear in all copies.
27 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
28 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
29 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
30 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
31 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
32 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
33 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
38 #if defined(MDB_VL32) || defined(__WIN64__)
39 #define _FILE_OFFSET_BITS 64
45 /* We use native NT APIs to setup the memory map, so that we can
46 * let the DB file grow incrementally instead of always preallocating
47 * the full size. These APIs are defined in <wdm.h> and <ntifs.h>
48 * but those headers are meant for driver-level development and
49 * conflict with the regular user-level headers, so we explicitly
50 * declare them here. Using these APIs also means we must link to
51 * ntdll.dll, which is not linked by default in user code.
54 NtCreateSection(OUT PHANDLE sh, IN ACCESS_MASK acc,
55 IN void * oa OPTIONAL,
56 IN PLARGE_INTEGER ms OPTIONAL,
57 IN ULONG pp, IN ULONG aa, IN HANDLE fh OPTIONAL);
59 typedef enum _SECTION_INHERIT {
65 NtMapViewOfSection(IN PHANDLE sh, IN HANDLE ph,
66 IN OUT PVOID *addr, IN ULONG_PTR zbits,
67 IN SIZE_T cs, IN OUT PLARGE_INTEGER off OPTIONAL,
68 IN OUT PSIZE_T vs, IN SECTION_INHERIT ih,
69 IN ULONG at, IN ULONG pp);
74 /** getpid() returns int; MinGW defines pid_t but MinGW64 typedefs it
75 * as int64 which is wrong. MSVC doesn't define it at all, so just
79 #define MDB_THR_T DWORD
80 #include <sys/types.h>
83 # include <sys/param.h>
85 # define LITTLE_ENDIAN 1234
86 # define BIG_ENDIAN 4321
87 # define BYTE_ORDER LITTLE_ENDIAN
89 # define SSIZE_MAX INT_MAX
93 #include <sys/types.h>
95 #define MDB_PID_T pid_t
96 #define MDB_THR_T pthread_t
97 #include <sys/param.h>
100 #ifdef HAVE_SYS_FILE_H
101 #include <sys/file.h>
106 #if defined(__mips) && defined(__linux)
107 /* MIPS has cache coherency issues, requires explicit cache control */
108 #include <asm/cachectl.h>
109 extern int cacheflush(char *addr, int nbytes, int cache);
110 #define CACHEFLUSH(addr, bytes, cache) cacheflush(addr, bytes, cache)
112 #define CACHEFLUSH(addr, bytes, cache)
115 #if defined(__linux) && !defined(MDB_FDATASYNC_WORKS)
116 /** fdatasync is broken on ext3/ext4fs on older kernels, see
117 * description in #mdb_env_open2 comments. You can safely
118 * define MDB_FDATASYNC_WORKS if this code will only be run
119 * on kernels 3.6 and newer.
121 #define BROKEN_FDATASYNC
127 #include <inttypes.h>
135 typedef SSIZE_T ssize_t;
140 #if defined(__sun) || defined(ANDROID)
141 /* Most platforms have posix_memalign, older may only have memalign */
142 #define HAVE_MEMALIGN 1
146 #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
147 #include <netinet/in.h>
148 #include <resolv.h> /* defines BYTE_ORDER on HPUX and Solaris */
151 #if defined(__APPLE__) || defined (BSD)
152 # if !(defined(MDB_USE_POSIX_MUTEX) || defined(MDB_USE_POSIX_SEM))
153 # define MDB_USE_SYSV_SEM 1
155 # define MDB_FDATASYNC fsync
156 #elif defined(ANDROID)
157 # define MDB_FDATASYNC fsync
162 #ifdef MDB_USE_POSIX_SEM
163 # define MDB_USE_HASH 1
164 #include <semaphore.h>
165 #elif defined(MDB_USE_SYSV_SEM)
168 #ifdef _SEM_SEMUN_UNDEFINED
171 struct semid_ds *buf;
172 unsigned short *array;
174 #endif /* _SEM_SEMUN_UNDEFINED */
176 #define MDB_USE_POSIX_MUTEX 1
177 #endif /* MDB_USE_POSIX_SEM */
180 #if defined(_WIN32) + defined(MDB_USE_POSIX_SEM) + defined(MDB_USE_SYSV_SEM) \
181 + defined(MDB_USE_POSIX_MUTEX) != 1
182 # error "Ambiguous shared-lock implementation"
186 #include <valgrind/memcheck.h>
187 #define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z)
188 #define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s)
189 #define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a)
190 #define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h)
191 #define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s)
193 #define VGMEMP_CREATE(h,r,z)
194 #define VGMEMP_ALLOC(h,a,s)
195 #define VGMEMP_FREE(h,a)
196 #define VGMEMP_DESTROY(h)
197 #define VGMEMP_DEFINED(a,s)
201 # if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN))
202 /* Solaris just defines one or the other */
203 # define LITTLE_ENDIAN 1234
204 # define BIG_ENDIAN 4321
205 # ifdef _LITTLE_ENDIAN
206 # define BYTE_ORDER LITTLE_ENDIAN
208 # define BYTE_ORDER BIG_ENDIAN
211 # define BYTE_ORDER __BYTE_ORDER
215 #ifndef LITTLE_ENDIAN
216 #define LITTLE_ENDIAN __LITTLE_ENDIAN
219 #define BIG_ENDIAN __BIG_ENDIAN
222 #if defined(__i386) || defined(__x86_64) || defined(_M_IX86)
223 #define MISALIGNED_OK 1
229 #if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN)
230 # error "Unknown or unsupported endianness (BYTE_ORDER)"
231 #elif (-6 & 5) || CHAR_BIT!=8 || UINT_MAX!=0xffffffff || MDB_SIZE_MAX%UINT_MAX
232 # error "Two's complement, reasonably sized integer types, please"
236 /** Put infrequently used env functions in separate section */
238 # define ESECT __attribute__ ((section("__TEXT,text_env")))
240 # define ESECT __attribute__ ((section("text_env")))
247 #define CALL_CONV WINAPI
252 /** @defgroup internal LMDB Internals
255 /** @defgroup compat Compatibility Macros
256 * A bunch of macros to minimize the amount of platform-specific ifdefs
257 * needed throughout the rest of the code. When the features this library
258 * needs are similar enough to POSIX to be hidden in a one-or-two line
259 * replacement, this macro approach is used.
263 /** Features under development */
268 /** Wrapper around __func__, which is a C99 feature */
269 #if __STDC_VERSION__ >= 199901L
270 # define mdb_func_ __func__
271 #elif __GNUC__ >= 2 || _MSC_VER >= 1300
272 # define mdb_func_ __FUNCTION__
274 /* If a debug message says <mdb_unknown>(), update the #if statements above */
275 # define mdb_func_ "<mdb_unknown>"
278 /* Internal error codes, not exposed outside liblmdb */
279 #define MDB_NO_ROOT (MDB_LAST_ERRCODE + 10)
281 #define MDB_OWNERDEAD ((int) WAIT_ABANDONED)
282 #elif defined MDB_USE_SYSV_SEM
283 #define MDB_OWNERDEAD (MDB_LAST_ERRCODE + 11)
284 #elif defined(MDB_USE_POSIX_MUTEX) && defined(EOWNERDEAD)
285 #define MDB_OWNERDEAD EOWNERDEAD /**< #LOCK_MUTEX0() result if dead owner */
289 #define GLIBC_VER ((__GLIBC__ << 16 )| __GLIBC_MINOR__)
291 /** Some platforms define the EOWNERDEAD error code
292 * even though they don't support Robust Mutexes.
293 * Compile with -DMDB_USE_ROBUST=0, or use some other
294 * mechanism like -DMDB_USE_SYSV_SEM instead of
295 * -DMDB_USE_POSIX_MUTEX. (SysV semaphores are
296 * also Robust, but some systems don't support them
299 #ifndef MDB_USE_ROBUST
300 /* Android currently lacks Robust Mutex support. So does glibc < 2.4. */
301 # if defined(MDB_USE_POSIX_MUTEX) && (defined(ANDROID) || \
302 (defined(__GLIBC__) && GLIBC_VER < 0x020004))
303 # define MDB_USE_ROBUST 0
305 # define MDB_USE_ROBUST 1
306 /* glibc < 2.12 only provided _np API */
307 # if (defined(__GLIBC__) && GLIBC_VER < 0x02000c) || \
308 (defined(PTHREAD_MUTEX_ROBUST_NP) && !defined(PTHREAD_MUTEX_ROBUST))
309 # define PTHREAD_MUTEX_ROBUST PTHREAD_MUTEX_ROBUST_NP
310 # define pthread_mutexattr_setrobust(attr, flag) pthread_mutexattr_setrobust_np(attr, flag)
311 # define pthread_mutex_consistent(mutex) pthread_mutex_consistent_np(mutex)
314 #endif /* MDB_USE_ROBUST */
316 #if defined(MDB_OWNERDEAD) && MDB_USE_ROBUST
317 #define MDB_ROBUST_SUPPORTED 1
321 #define MDB_USE_HASH 1
322 #define MDB_PIDLOCK 0
323 #define THREAD_RET DWORD
324 #define pthread_t HANDLE
325 #define pthread_mutex_t HANDLE
326 #define pthread_cond_t HANDLE
327 typedef HANDLE mdb_mutex_t, mdb_mutexref_t;
328 #define pthread_key_t DWORD
329 #define pthread_self() GetCurrentThreadId()
330 #define pthread_key_create(x,y) \
331 ((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
332 #define pthread_key_delete(x) TlsFree(x)
333 #define pthread_getspecific(x) TlsGetValue(x)
334 #define pthread_setspecific(x,y) (TlsSetValue(x,y) ? 0 : ErrCode())
335 #define pthread_mutex_unlock(x) ReleaseMutex(*x)
336 #define pthread_mutex_lock(x) WaitForSingleObject(*x, INFINITE)
337 #define pthread_cond_signal(x) SetEvent(*x)
338 #define pthread_cond_wait(cond,mutex) do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0)
339 #define THREAD_CREATE(thr,start,arg) \
340 (((thr) = CreateThread(NULL, 0, start, arg, 0, NULL)) ? 0 : ErrCode())
341 #define THREAD_FINISH(thr) \
342 (WaitForSingleObject(thr, INFINITE) ? ErrCode() : 0)
343 #define LOCK_MUTEX0(mutex) WaitForSingleObject(mutex, INFINITE)
344 #define UNLOCK_MUTEX(mutex) ReleaseMutex(mutex)
345 #define mdb_mutex_consistent(mutex) 0
346 #define getpid() GetCurrentProcessId()
347 #define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd))
348 #define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len))
349 #define ErrCode() GetLastError()
350 #define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;}
351 #define close(fd) (CloseHandle(fd) ? 0 : -1)
352 #define munmap(ptr,len) UnmapViewOfFile(ptr)
353 #ifdef PROCESS_QUERY_LIMITED_INFORMATION
354 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION PROCESS_QUERY_LIMITED_INFORMATION
356 #define MDB_PROCESS_QUERY_LIMITED_INFORMATION 0x1000
359 #define THREAD_RET void *
360 #define THREAD_CREATE(thr,start,arg) pthread_create(&thr,NULL,start,arg)
361 #define THREAD_FINISH(thr) pthread_join(thr,NULL)
363 /** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */
364 #define MDB_PIDLOCK 1
366 #ifdef MDB_USE_POSIX_SEM
368 typedef sem_t *mdb_mutex_t, *mdb_mutexref_t;
369 #define LOCK_MUTEX0(mutex) mdb_sem_wait(mutex)
370 #define UNLOCK_MUTEX(mutex) sem_post(mutex)
373 mdb_sem_wait(sem_t *sem)
376 while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
380 #elif defined MDB_USE_SYSV_SEM
382 typedef struct mdb_mutex {
386 } mdb_mutex_t[1], *mdb_mutexref_t;
388 #define LOCK_MUTEX0(mutex) mdb_sem_wait(mutex)
389 #define UNLOCK_MUTEX(mutex) do { \
390 struct sembuf sb = { 0, 1, SEM_UNDO }; \
391 sb.sem_num = (mutex)->semnum; \
392 *(mutex)->locked = 0; \
393 semop((mutex)->semid, &sb, 1); \
397 mdb_sem_wait(mdb_mutexref_t sem)
399 int rc, *locked = sem->locked;
400 struct sembuf sb = { 0, -1, SEM_UNDO };
401 sb.sem_num = sem->semnum;
403 if (!semop(sem->semid, &sb, 1)) {
404 rc = *locked ? MDB_OWNERDEAD : MDB_SUCCESS;
408 } while ((rc = errno) == EINTR);
412 #define mdb_mutex_consistent(mutex) 0
414 #else /* MDB_USE_POSIX_MUTEX: */
415 /** Shared mutex/semaphore as it is stored (mdb_mutex_t), and as
416 * local variables keep it (mdb_mutexref_t).
418 * An mdb_mutex_t can be assigned to an mdb_mutexref_t. They can
419 * be the same, or an array[size 1] and a pointer.
422 typedef pthread_mutex_t mdb_mutex_t[1], *mdb_mutexref_t;
424 /** Lock the reader or writer mutex.
425 * Returns 0 or a code to give #mdb_mutex_failed(), as in #LOCK_MUTEX().
427 #define LOCK_MUTEX0(mutex) pthread_mutex_lock(mutex)
428 /** Unlock the reader or writer mutex.
430 #define UNLOCK_MUTEX(mutex) pthread_mutex_unlock(mutex)
431 /** Mark mutex-protected data as repaired, after death of previous owner.
433 #define mdb_mutex_consistent(mutex) pthread_mutex_consistent(mutex)
434 #endif /* MDB_USE_POSIX_SEM || MDB_USE_SYSV_SEM */
436 /** Get the error code for the last failed system function.
438 #define ErrCode() errno
440 /** An abstraction for a file handle.
441 * On POSIX systems file handles are small integers. On Windows
442 * they're opaque pointers.
446 /** A value for an invalid file handle.
447 * Mainly used to initialize file variables and signify that they are
450 #define INVALID_HANDLE_VALUE (-1)
452 /** Get the size of a memory page for the system.
453 * This is the basic size that the platform's memory manager uses, and is
454 * fundamental to the use of memory-mapped files.
456 #define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE))
459 #define Z MDB_FMT_Z /**< printf/scanf format modifier for size_t */
460 #define Y MDB_FMT_Y /**< printf/scanf format modifier for #mdb_size_t */
462 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
464 #elif defined(MDB_USE_SYSV_SEM)
465 #define MNAME_LEN (sizeof(int))
467 #define MNAME_LEN (sizeof(pthread_mutex_t))
470 #ifdef MDB_USE_SYSV_SEM
471 #define SYSV_SEM_FLAG 1 /**< SysV sems in lockfile format */
473 #define SYSV_SEM_FLAG 0
478 #ifdef MDB_ROBUST_SUPPORTED
479 /** Lock mutex, handle any error, set rc = result.
480 * Return 0 on success, nonzero (not rc) on error.
482 #define LOCK_MUTEX(rc, env, mutex) \
483 (((rc) = LOCK_MUTEX0(mutex)) && \
484 ((rc) = mdb_mutex_failed(env, mutex, rc)))
485 static int mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc);
487 #define LOCK_MUTEX(rc, env, mutex) ((rc) = LOCK_MUTEX0(mutex))
488 #define mdb_mutex_failed(env, mutex, rc) (rc)
492 /** A flag for opening a file and requesting synchronous data writes.
493 * This is only used when writing a meta page. It's not strictly needed;
494 * we could just do a normal write and then immediately perform a flush.
495 * But if this flag is available it saves us an extra system call.
497 * @note If O_DSYNC is undefined but exists in /usr/include,
498 * preferably set some compiler flag to get the definition.
502 # define MDB_DSYNC O_DSYNC
504 # define MDB_DSYNC O_SYNC
509 /** Function for flushing the data of a file. Define this to fsync
510 * if fdatasync() is not supported.
512 #ifndef MDB_FDATASYNC
513 # define MDB_FDATASYNC fdatasync
517 # define MDB_MSYNC(addr,len,flags) msync(addr,len,flags)
528 /** A page number in the database.
529 * Note that 64 bit page numbers are overkill, since pages themselves
530 * already represent 12-13 bits of addressable memory, and the OS will
531 * always limit applications to a maximum of 63 bits of address space.
533 * @note In the #MDB_node structure, we only store 48 bits of this value,
534 * which thus limits us to only 60 bits of addressable data.
536 typedef MDB_ID pgno_t;
538 /** A transaction ID.
539 * See struct MDB_txn.mt_txnid for details.
541 typedef MDB_ID txnid_t;
543 /** @defgroup debug Debug Macros
547 /** Enable debug output. Needs variable argument macros (a C99 feature).
548 * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs
549 * read from and written to the database (used for free space management).
555 static int mdb_debug;
556 static txnid_t mdb_debug_start;
558 /** Print a debug message with printf formatting.
559 * Requires double parenthesis around 2 or more args.
561 # define DPRINTF(args) ((void) ((mdb_debug) && DPRINTF0 args))
562 # define DPRINTF0(fmt, ...) \
563 fprintf(stderr, "%s:%d " fmt "\n", mdb_func_, __LINE__, __VA_ARGS__)
565 # define DPRINTF(args) ((void) 0)
567 /** Print a debug string.
568 * The string is printed literally, with no format processing.
570 #define DPUTS(arg) DPRINTF(("%s", arg))
571 /** Debuging output value of a cursor DBI: Negative in a sub-cursor. */
573 (((mc)->mc_flags & C_SUB) ? -(int)(mc)->mc_dbi : (int)(mc)->mc_dbi)
576 /** @brief The maximum size of a database page.
578 * It is 32k or 64k, since value-PAGEBASE must fit in
579 * #MDB_page.%mp_upper.
581 * LMDB will use database pages < OS pages if needed.
582 * That causes more I/O in write transactions: The OS must
583 * know (read) the whole page before writing a partial page.
585 * Note that we don't currently support Huge pages. On Linux,
586 * regular data files cannot use Huge pages, and in general
587 * Huge pages aren't actually pageable. We rely on the OS
588 * demand-pager to read our data and page it out when memory
589 * pressure from other processes is high. So until OSs have
590 * actual paging support for Huge pages, they're not viable.
592 #define MAX_PAGESIZE (PAGEBASE ? 0x10000 : 0x8000)
594 /** The minimum number of keys required in a database page.
595 * Setting this to a larger value will place a smaller bound on the
596 * maximum size of a data item. Data items larger than this size will
597 * be pushed into overflow pages instead of being stored directly in
598 * the B-tree node. This value used to default to 4. With a page size
599 * of 4096 bytes that meant that any item larger than 1024 bytes would
600 * go into an overflow page. That also meant that on average 2-3KB of
601 * each overflow page was wasted space. The value cannot be lower than
602 * 2 because then there would no longer be a tree structure. With this
603 * value, items larger than 2KB will go into overflow pages, and on
604 * average only 1KB will be wasted.
606 #define MDB_MINKEYS 2
608 /** A stamp that identifies a file as an LMDB file.
609 * There's nothing special about this value other than that it is easily
610 * recognizable, and it will reflect any byte order mismatches.
612 #define MDB_MAGIC 0xBEEFC0DE
614 /** The version number for a database's datafile format. */
615 #define MDB_DATA_VERSION ((MDB_DEVEL) ? 999 : 1)
616 /** The version number for a database's lockfile format. */
617 #define MDB_LOCK_VERSION ((MDB_DEVEL) ? 999 : 1)
619 /** @brief The max size of a key we can write, or 0 for computed max.
621 * This macro should normally be left alone or set to 0.
622 * Note that a database with big keys or dupsort data cannot be
623 * reliably modified by a liblmdb which uses a smaller max.
624 * The default is 511 for backwards compat, or 0 when #MDB_DEVEL.
626 * Other values are allowed, for backwards compat. However:
627 * A value bigger than the computed max can break if you do not
628 * know what you are doing, and liblmdb <= 0.9.10 can break when
629 * modifying a DB with keys/dupsort data bigger than its max.
631 * Data items in an #MDB_DUPSORT database are also limited to
632 * this size, since they're actually keys of a sub-DB. Keys and
633 * #MDB_DUPSORT data items must fit on a node in a regular page.
635 #ifndef MDB_MAXKEYSIZE
636 #define MDB_MAXKEYSIZE ((MDB_DEVEL) ? 0 : 511)
639 /** The maximum size of a key we can write to the environment. */
641 #define ENV_MAXKEY(env) (MDB_MAXKEYSIZE)
643 #define ENV_MAXKEY(env) ((env)->me_maxkey)
646 /** @brief The maximum size of a data item.
648 * We only store a 32 bit value for node sizes.
650 #define MAXDATASIZE 0xffffffffUL
653 /** Key size which fits in a #DKBUF.
656 #define DKBUF_MAXKEYSIZE ((MDB_MAXKEYSIZE) > 0 ? (MDB_MAXKEYSIZE) : 511)
659 * This is used for printing a hex dump of a key's contents.
661 #define DKBUF char kbuf[DKBUF_MAXKEYSIZE*2+1]
662 /** Display a key in hex.
664 * Invoke a function to display a key in hex.
666 #define DKEY(x) mdb_dkey(x, kbuf)
672 /** An invalid page number.
673 * Mainly used to denote an empty tree.
675 #define P_INVALID (~(pgno_t)0)
677 /** Test if the flags \b f are set in a flag word \b w. */
678 #define F_ISSET(w, f) (((w) & (f)) == (f))
680 /** Round \b n up to an even number. */
681 #define EVEN(n) (((n) + 1U) & -2) /* sign-extending -2 to match n+1U */
683 /** Used for offsets within a single page.
684 * Since memory pages are typically 4 or 8KB in size, 12-13 bits,
687 typedef uint16_t indx_t;
689 /** Default size of memory map.
690 * This is certainly too small for any actual applications. Apps should always set
691 * the size explicitly using #mdb_env_set_mapsize().
693 #define DEFAULT_MAPSIZE 1048576
695 /** @defgroup readers Reader Lock Table
696 * Readers don't acquire any locks for their data access. Instead, they
697 * simply record their transaction ID in the reader table. The reader
698 * mutex is needed just to find an empty slot in the reader table. The
699 * slot's address is saved in thread-specific data so that subsequent read
700 * transactions started by the same thread need no further locking to proceed.
702 * If #MDB_NOTLS is set, the slot address is not saved in thread-specific data.
704 * No reader table is used if the database is on a read-only filesystem, or
705 * if #MDB_NOLOCK is set.
707 * Since the database uses multi-version concurrency control, readers don't
708 * actually need any locking. This table is used to keep track of which
709 * readers are using data from which old transactions, so that we'll know
710 * when a particular old transaction is no longer in use. Old transactions
711 * that have discarded any data pages can then have those pages reclaimed
712 * for use by a later write transaction.
714 * The lock table is constructed such that reader slots are aligned with the
715 * processor's cache line size. Any slot is only ever used by one thread.
716 * This alignment guarantees that there will be no contention or cache
717 * thrashing as threads update their own slot info, and also eliminates
718 * any need for locking when accessing a slot.
720 * A writer thread will scan every slot in the table to determine the oldest
721 * outstanding reader transaction. Any freed pages older than this will be
722 * reclaimed by the writer. The writer doesn't use any locks when scanning
723 * this table. This means that there's no guarantee that the writer will
724 * see the most up-to-date reader info, but that's not required for correct
725 * operation - all we need is to know the upper bound on the oldest reader,
726 * we don't care at all about the newest reader. So the only consequence of
727 * reading stale information here is that old pages might hang around a
728 * while longer before being reclaimed. That's actually good anyway, because
729 * the longer we delay reclaiming old pages, the more likely it is that a
730 * string of contiguous pages can be found after coalescing old pages from
731 * many old transactions together.
734 /** Number of slots in the reader table.
735 * This value was chosen somewhat arbitrarily. 126 readers plus a
736 * couple mutexes fit exactly into 8KB on my development machine.
737 * Applications should set the table size using #mdb_env_set_maxreaders().
739 #define DEFAULT_READERS 126
741 /** The size of a CPU cache line in bytes. We want our lock structures
742 * aligned to this size to avoid false cache line sharing in the
744 * This value works for most CPUs. For Itanium this should be 128.
750 /** The information we store in a single slot of the reader table.
751 * In addition to a transaction ID, we also record the process and
752 * thread ID that owns a slot, so that we can detect stale information,
753 * e.g. threads or processes that went away without cleaning up.
754 * @note We currently don't check for stale records. We simply re-init
755 * the table when we know that we're the only process opening the
758 typedef struct MDB_rxbody {
759 /** Current Transaction ID when this transaction began, or (txnid_t)-1.
760 * Multiple readers that start at the same time will probably have the
761 * same ID here. Again, it's not important to exclude them from
762 * anything; all we need to know is which version of the DB they
763 * started from so we can avoid overwriting any data used in that
764 * particular version.
766 volatile txnid_t mrb_txnid;
767 /** The process ID of the process owning this reader txn. */
768 volatile MDB_PID_T mrb_pid;
769 /** The thread ID of the thread owning this txn. */
770 volatile MDB_THR_T mrb_tid;
773 /** The actual reader record, with cacheline padding. */
774 typedef struct MDB_reader {
777 /** shorthand for mrb_txnid */
778 #define mr_txnid mru.mrx.mrb_txnid
779 #define mr_pid mru.mrx.mrb_pid
780 #define mr_tid mru.mrx.mrb_tid
781 /** cache line alignment */
782 char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)];
786 /** The header for the reader table.
787 * The table resides in a memory-mapped file. (This is a different file
788 * than is used for the main database.)
790 * For POSIX the actual mutexes reside in the shared memory of this
791 * mapped file. On Windows, mutexes are named objects allocated by the
792 * kernel; we store the mutex names in this mapped file so that other
793 * processes can grab them. This same approach is also used on
794 * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support
795 * process-shared POSIX mutexes. For these cases where a named object
796 * is used, the object name is derived from a 64 bit FNV hash of the
797 * environment pathname. As such, naming collisions are extremely
798 * unlikely. If a collision occurs, the results are unpredictable.
800 typedef struct MDB_txbody {
801 /** Stamp identifying this as an LMDB file. It must be set
804 /** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */
806 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
807 char mtb_rmname[MNAME_LEN];
808 #elif defined(MDB_USE_SYSV_SEM)
812 /** Mutex protecting access to this table.
813 * This is the reader table lock used with LOCK_MUTEX().
815 mdb_mutex_t mtb_rmutex;
817 /** The ID of the last transaction committed to the database.
818 * This is recorded here only for convenience; the value can always
819 * be determined by reading the main database meta pages.
821 volatile txnid_t mtb_txnid;
822 /** The number of slots that have been used in the reader table.
823 * This always records the maximum count, it is not decremented
824 * when readers release their slots.
826 volatile unsigned mtb_numreaders;
829 /** The actual reader table definition. */
830 typedef struct MDB_txninfo {
833 #define mti_magic mt1.mtb.mtb_magic
834 #define mti_format mt1.mtb.mtb_format
835 #define mti_rmutex mt1.mtb.mtb_rmutex
836 #define mti_rmname mt1.mtb.mtb_rmname
837 #define mti_txnid mt1.mtb.mtb_txnid
838 #define mti_numreaders mt1.mtb.mtb_numreaders
839 #ifdef MDB_USE_SYSV_SEM
840 #define mti_semid mt1.mtb.mtb_semid
841 #define mti_rlocked mt1.mtb.mtb_rlocked
843 char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
846 #if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
847 char mt2_wmname[MNAME_LEN];
848 #define mti_wmname mt2.mt2_wmname
849 #elif defined MDB_USE_SYSV_SEM
851 #define mti_wlocked mt2.mt2_wlocked
853 mdb_mutex_t mt2_wmutex;
854 #define mti_wmutex mt2.mt2_wmutex
856 char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)];
858 MDB_reader mti_readers[1];
861 /** Lockfile format signature: version, features and field layout */
862 #define MDB_LOCK_FORMAT \
864 ((MDB_LOCK_VERSION) \
865 /* Flags which describe functionality */ \
866 + (SYSV_SEM_FLAG << 18) \
867 + (((MDB_PIDLOCK) != 0) << 16)))
870 /** Common header for all page types.
871 * Overflow records occupy a number of contiguous pages with no
872 * headers on any page after the first.
874 typedef struct MDB_page {
875 #define mp_pgno mp_p.p_pgno
876 #define mp_next mp_p.p_next
878 pgno_t p_pgno; /**< page number */
879 struct MDB_page *p_next; /**< for in-memory list of freed pages */
882 /** @defgroup mdb_page Page Flags
884 * Flags for the page headers.
887 #define P_BRANCH 0x01 /**< branch page */
888 #define P_LEAF 0x02 /**< leaf page */
889 #define P_OVERFLOW 0x04 /**< overflow page */
890 #define P_META 0x08 /**< meta page */
891 #define P_DIRTY 0x10 /**< dirty page, also set for #P_SUBP pages */
892 #define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */
893 #define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */
894 #define P_LOOSE 0x4000 /**< page was dirtied then freed, can be reused */
895 #define P_KEEP 0x8000 /**< leave this page alone during spill */
897 uint16_t mp_flags; /**< @ref mdb_page */
898 #define mp_lower mp_pb.pb.pb_lower
899 #define mp_upper mp_pb.pb.pb_upper
900 #define mp_pages mp_pb.pb_pages
903 indx_t pb_lower; /**< lower bound of free space */
904 indx_t pb_upper; /**< upper bound of free space */
906 uint32_t pb_pages; /**< number of overflow pages */
908 indx_t mp_ptrs[1]; /**< dynamic size */
911 /** Size of the page header, excluding dynamic data at the end */
912 #define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs))
914 /** Address of first usable data byte in a page, after the header */
915 #define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ))
917 /** ITS#7713, change PAGEBASE to handle 65536 byte pages */
918 #define PAGEBASE ((MDB_DEVEL) ? PAGEHDRSZ : 0)
920 /** Number of nodes on a page */
921 #define NUMKEYS(p) (((p)->mp_lower - (PAGEHDRSZ-PAGEBASE)) >> 1)
923 /** The amount of space remaining in the page */
924 #define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
926 /** The percentage of space used in the page, in tenths of a percent. */
927 #define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \
928 ((env)->me_psize - PAGEHDRSZ))
929 /** The minimum page fill factor, in tenths of a percent.
930 * Pages emptier than this are candidates for merging.
932 #define FILL_THRESHOLD 250
934 /** Test if a page is a leaf page */
935 #define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
936 /** Test if a page is a LEAF2 page */
937 #define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2)
938 /** Test if a page is a branch page */
939 #define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
940 /** Test if a page is an overflow page */
941 #define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
942 /** Test if a page is a sub page */
943 #define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP)
945 /** The number of overflow pages needed to store the given size. */
946 #define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1)
948 /** Link in #MDB_txn.%mt_loose_pgs list */
949 #define NEXT_LOOSE_PAGE(p) (*(MDB_page **)((p) + 2))
951 /** Header for a single key/data pair within a page.
952 * Used in pages of type #P_BRANCH and #P_LEAF without #P_LEAF2.
953 * We guarantee 2-byte alignment for 'MDB_node's.
955 typedef struct MDB_node {
956 /** lo and hi are used for data size on leaf nodes and for
957 * child pgno on branch nodes. On 64 bit platforms, flags
958 * is also used for pgno. (Branch nodes have no flags).
959 * They are in host byte order in case that lets some
960 * accesses be optimized into a 32-bit word access.
962 #if BYTE_ORDER == LITTLE_ENDIAN
963 unsigned short mn_lo, mn_hi; /**< part of data size or pgno */
965 unsigned short mn_hi, mn_lo;
967 /** @defgroup mdb_node Node Flags
969 * Flags for node headers.
972 #define F_BIGDATA 0x01 /**< data put on overflow page */
973 #define F_SUBDATA 0x02 /**< data is a sub-database */
974 #define F_DUPDATA 0x04 /**< data has duplicates */
976 /** valid flags for #mdb_node_add() */
977 #define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND)
980 unsigned short mn_flags; /**< @ref mdb_node */
981 unsigned short mn_ksize; /**< key size */
982 char mn_data[1]; /**< key and data are appended here */
985 /** Size of the node header, excluding dynamic data at the end */
986 #define NODESIZE offsetof(MDB_node, mn_data)
988 /** Bit position of top word in page number, for shifting mn_flags */
989 #define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0)
991 /** Size of a node in a branch page with a given key.
992 * This is just the node header plus the key, there is no data.
994 #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
996 /** Size of a node in a leaf page with a given key and data.
997 * This is node header plus key plus data size.
999 #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
1001 /** Address of node \b i in page \b p */
1002 #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i] + PAGEBASE))
1004 /** Address of the key for the node */
1005 #define NODEKEY(node) (void *)((node)->mn_data)
1007 /** Address of the data for a node */
1008 #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
1010 /** Get the page number pointed to by a branch node */
1011 #define NODEPGNO(node) \
1012 ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \
1013 (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
1014 /** Set the page number in a branch node */
1015 #define SETPGNO(node,pgno) do { \
1016 (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \
1017 if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
1019 /** Get the size of the data in a leaf node */
1020 #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
1021 /** Set the size of the data for a leaf node */
1022 #define SETDSZ(node,size) do { \
1023 (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
1024 /** The size of a key in a node */
1025 #define NODEKSZ(node) ((node)->mn_ksize)
1027 /** Copy a page number from src to dst */
1028 #ifdef MISALIGNED_OK
1029 #define COPY_PGNO(dst,src) dst = src
1031 #if MDB_SIZE_MAX > 0xffffffffU
1032 #define COPY_PGNO(dst,src) do { \
1033 unsigned short *s, *d; \
1034 s = (unsigned short *)&(src); \
1035 d = (unsigned short *)&(dst); \
1042 #define COPY_PGNO(dst,src) do { \
1043 unsigned short *s, *d; \
1044 s = (unsigned short *)&(src); \
1045 d = (unsigned short *)&(dst); \
1051 /** The address of a key in a LEAF2 page.
1052 * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs.
1053 * There are no node headers, keys are stored contiguously.
1055 #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
1057 /** Set the \b node's key into \b keyptr, if requested. */
1058 #define MDB_GET_KEY(node, keyptr) { if ((keyptr) != NULL) { \
1059 (keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }
1061 /** Set the \b node's key into \b key. */
1062 #define MDB_GET_KEY2(node, key) { key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }
1064 /** Information about a single database in the environment. */
1065 typedef struct MDB_db {
1066 uint32_t md_pad; /**< also ksize for LEAF2 pages */
1067 uint16_t md_flags; /**< @ref mdb_dbi_open */
1068 uint16_t md_depth; /**< depth of this tree */
1069 pgno_t md_branch_pages; /**< number of internal pages */
1070 pgno_t md_leaf_pages; /**< number of leaf pages */
1071 pgno_t md_overflow_pages; /**< number of overflow pages */
1072 mdb_size_t md_entries; /**< number of data items */
1073 pgno_t md_root; /**< the root page of this tree */
1076 /** mdb_dbi_open flags */
1077 #define MDB_VALID 0x8000 /**< DB handle is valid, for me_dbflags */
1078 #define PERSISTENT_FLAGS (0xffff & ~(MDB_VALID))
1079 #define VALID_FLAGS (MDB_REVERSEKEY|MDB_DUPSORT|MDB_INTEGERKEY|MDB_DUPFIXED|\
1080 MDB_INTEGERDUP|MDB_REVERSEDUP|MDB_CREATE)
1082 /** Handle for the DB used to track free pages. */
1084 /** Handle for the default DB. */
1086 /** Number of DBs in metapage (free and main) - also hardcoded elsewhere */
1089 /** Number of meta pages - also hardcoded elsewhere */
1092 /** Meta page content.
1093 * A meta page is the start point for accessing a database snapshot.
1094 * Pages 0-1 are meta pages. Transaction N writes meta page #(N % 2).
1096 typedef struct MDB_meta {
1097 /** Stamp identifying this as an LMDB file. It must be set
1100 /** Version number of this file. Must be set to #MDB_DATA_VERSION. */
1101 uint32_t mm_version;
1103 union { /* always zero since we don't support fixed mapping in MDB_VL32 */
1107 #define mm_address mm_un.mmun_address
1109 void *mm_address; /**< address for fixed mapping */
1111 pgno_t mm_mapsize; /**< size of mmap region */
1112 MDB_db mm_dbs[CORE_DBS]; /**< first is free space, 2nd is main db */
1113 /** The size of pages used in this DB */
1114 #define mm_psize mm_dbs[FREE_DBI].md_pad
1115 /** Any persistent environment flags. @ref mdb_env */
1116 #define mm_flags mm_dbs[FREE_DBI].md_flags
1117 pgno_t mm_last_pg; /**< last used page in file */
1118 volatile txnid_t mm_txnid; /**< txnid that committed this page */
1121 /** Buffer for a stack-allocated meta page.
1122 * The members define size and alignment, and silence type
1123 * aliasing warnings. They are not used directly; that could
1124 * mean incorrectly using several union members in parallel.
1126 typedef union MDB_metabuf {
1129 char mm_pad[PAGEHDRSZ];
1134 /** Auxiliary DB info.
1135 * The information here is mostly static/read-only. There is
1136 * only a single copy of this record in the environment.
1138 typedef struct MDB_dbx {
1139 MDB_val md_name; /**< name of the database */
1140 MDB_cmp_func *md_cmp; /**< function for comparing keys */
1141 MDB_cmp_func *md_dcmp; /**< function for comparing data items */
1142 MDB_rel_func *md_rel; /**< user relocate function */
1143 void *md_relctx; /**< user-provided context for md_rel */
1146 /** A database transaction.
1147 * Every operation requires a transaction handle.
1150 MDB_txn *mt_parent; /**< parent of a nested txn */
1151 /** Nested txn under this txn, set together with flag #MDB_TXN_HAS_CHILD */
1153 pgno_t mt_next_pgno; /**< next unallocated page */
1155 pgno_t mt_last_pgno; /**< last written page */
1157 /** The ID of this transaction. IDs are integers incrementing from 1.
1158 * Only committed write transactions increment the ID. If a transaction
1159 * aborts, the ID may be re-used by the next writer.
1162 MDB_env *mt_env; /**< the DB environment */
1163 /** The list of pages that became unused during this transaction.
1165 MDB_IDL mt_free_pgs;
1166 /** The list of loose pages that became unused and may be reused
1167 * in this transaction, linked through #NEXT_LOOSE_PAGE(page).
1169 MDB_page *mt_loose_pgs;
1170 /* #Number of loose pages (#mt_loose_pgs) */
1172 /** The sorted list of dirty pages we temporarily wrote to disk
1173 * because the dirty list was full. page numbers in here are
1174 * shifted left by 1, deleted slots have the LSB set.
1176 MDB_IDL mt_spill_pgs;
1178 /** For write txns: Modified pages. Sorted when not MDB_WRITEMAP. */
1179 MDB_ID2L dirty_list;
1180 /** For read txns: This thread/txn's reader table slot, or NULL. */
1183 /** Array of records for each DB known in the environment. */
1185 /** Array of MDB_db records for each known DB */
1187 /** Array of sequence numbers for each DB handle */
1188 unsigned int *mt_dbiseqs;
1189 /** @defgroup mt_dbflag Transaction DB Flags
1193 #define DB_DIRTY 0x01 /**< DB was modified or is DUPSORT data */
1194 #define DB_STALE 0x02 /**< Named-DB record is older than txnID */
1195 #define DB_NEW 0x04 /**< Named-DB handle opened in this txn */
1196 #define DB_VALID 0x08 /**< DB handle is valid, see also #MDB_VALID */
1197 #define DB_USRVALID 0x10 /**< As #DB_VALID, but not set for #FREE_DBI */
1199 /** In write txns, array of cursors for each DB */
1200 MDB_cursor **mt_cursors;
1201 /** Array of flags for each DB */
1202 unsigned char *mt_dbflags;
1204 /** List of read-only pages (actually chunks) */
1206 /** We map chunks of 16 pages. Even though Windows uses 4KB pages, all
1207 * mappings must begin on 64KB boundaries. So we round off all pgnos to
1208 * a chunk boundary. We do the same on Linux for symmetry, and also to
1209 * reduce the frequency of mmap/munmap calls.
1211 #define MDB_RPAGE_CHUNK 16
1212 #define MDB_TRPAGE_SIZE 4096 /**< size of #mt_rpages array of chunks */
1213 #define MDB_TRPAGE_MAX (MDB_TRPAGE_SIZE-1) /**< maximum chunk index */
1214 unsigned int mt_rpcheck; /**< threshold for reclaiming unref'd chunks */
1216 /** Number of DB records in use, or 0 when the txn is finished.
1217 * This number only ever increments until the txn finishes; we
1218 * don't decrement it when individual DB handles are closed.
1222 /** @defgroup mdb_txn Transaction Flags
1226 /** #mdb_txn_begin() flags */
1227 #define MDB_TXN_BEGIN_FLAGS (MDB_NOMETASYNC|MDB_NOSYNC|MDB_RDONLY)
1228 #define MDB_TXN_NOMETASYNC MDB_NOMETASYNC /**< don't sync meta for this txn on commit */
1229 #define MDB_TXN_NOSYNC MDB_NOSYNC /**< don't sync this txn on commit */
1230 #define MDB_TXN_RDONLY MDB_RDONLY /**< read-only transaction */
1231 /* internal txn flags */
1232 #define MDB_TXN_WRITEMAP MDB_WRITEMAP /**< copy of #MDB_env flag in writers */
1233 #define MDB_TXN_FINISHED 0x01 /**< txn is finished or never began */
1234 #define MDB_TXN_ERROR 0x02 /**< txn is unusable after an error */
1235 #define MDB_TXN_DIRTY 0x04 /**< must write, even if dirty list is empty */
1236 #define MDB_TXN_SPILLS 0x08 /**< txn or a parent has spilled pages */
1237 #define MDB_TXN_HAS_CHILD 0x10 /**< txn has an #MDB_txn.%mt_child */
1238 /** most operations on the txn are currently illegal */
1239 #define MDB_TXN_BLOCKED (MDB_TXN_FINISHED|MDB_TXN_ERROR|MDB_TXN_HAS_CHILD)
1241 unsigned int mt_flags; /**< @ref mdb_txn */
1242 /** #dirty_list room: Array size - \#dirty pages visible to this txn.
1243 * Includes ancestor txns' dirty pages not hidden by other txns'
1244 * dirty/spilled pages. Thus commit(nested txn) has room to merge
1245 * dirty_list into mt_parent after freeing hidden mt_parent pages.
1247 unsigned int mt_dirty_room;
1250 /** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty.
1251 * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to
1252 * raise this on a 64 bit machine.
1254 #define CURSOR_STACK 32
1258 /** Cursors are used for all DB operations.
1259 * A cursor holds a path of (page pointer, key index) from the DB
1260 * root to a position in the DB, plus other state. #MDB_DUPSORT
1261 * cursors include an xcursor to the current data item. Write txns
1262 * track their cursors and keep them up to date when data moves.
1263 * Exception: An xcursor's pointer to a #P_SUBP page can be stale.
1264 * (A node with #F_DUPDATA but no #F_SUBDATA contains a subpage).
1267 /** Next cursor on this DB in this txn */
1268 MDB_cursor *mc_next;
1269 /** Backup of the original cursor if this cursor is a shadow */
1270 MDB_cursor *mc_backup;
1271 /** Context used for databases with #MDB_DUPSORT, otherwise NULL */
1272 struct MDB_xcursor *mc_xcursor;
1273 /** The transaction that owns this cursor */
1275 /** The database handle this cursor operates on */
1277 /** The database record for this cursor */
1279 /** The database auxiliary record for this cursor */
1281 /** The @ref mt_dbflag for this database */
1282 unsigned char *mc_dbflag;
1283 unsigned short mc_snum; /**< number of pushed pages */
1284 unsigned short mc_top; /**< index of top page, normally mc_snum-1 */
1285 /** @defgroup mdb_cursor Cursor Flags
1287 * Cursor state flags.
1290 #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */
1291 #define C_EOF 0x02 /**< No more data */
1292 #define C_SUB 0x04 /**< Cursor is a sub-cursor */
1293 #define C_DEL 0x08 /**< last op was a cursor_del */
1294 #define C_UNTRACK 0x40 /**< Un-track cursor when closing */
1295 #define C_WRITEMAP MDB_TXN_WRITEMAP /**< Copy of txn flag */
1296 /** Read-only cursor into the txn's original snapshot in the map.
1297 * Set for read-only txns, and in #mdb_page_alloc() for #FREE_DBI when
1298 * #MDB_DEVEL & 2. Only implements code which is necessary for this.
1300 #define C_ORIG_RDONLY MDB_TXN_RDONLY
1302 unsigned int mc_flags; /**< @ref mdb_cursor */
1303 MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */
1304 indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */
1306 MDB_page *mc_ovpg; /**< a referenced overflow page */
1307 # define MC_OVPG(mc) ((mc)->mc_ovpg)
1308 # define MC_SET_OVPG(mc, pg) ((mc)->mc_ovpg = (pg))
1310 # define MC_OVPG(mc) ((MDB_page *)0)
1311 # define MC_SET_OVPG(mc, pg) ((void)0)
1315 /** Context for sorted-dup records.
1316 * We could have gone to a fully recursive design, with arbitrarily
1317 * deep nesting of sub-databases. But for now we only handle these
1318 * levels - main DB, optional sub-DB, sorted-duplicate DB.
1320 typedef struct MDB_xcursor {
1321 /** A sub-cursor for traversing the Dup DB */
1322 MDB_cursor mx_cursor;
1323 /** The database record for this Dup DB */
1325 /** The auxiliary DB record for this Dup DB */
1327 /** The @ref mt_dbflag for this Dup DB */
1328 unsigned char mx_dbflag;
1331 /** State of FreeDB old pages, stored in the MDB_env */
1332 typedef struct MDB_pgstate {
1333 pgno_t *mf_pghead; /**< Reclaimed freeDB pages, or NULL before use */
1334 txnid_t mf_pglast; /**< ID of last used record, or 0 if !mf_pghead */
1337 /** The database environment. */
1339 HANDLE me_fd; /**< The main data file */
1340 HANDLE me_lfd; /**< The lock file */
1341 HANDLE me_mfd; /**< just for writing the meta pages */
1342 #if defined(MDB_VL32) && defined(_WIN32)
1343 HANDLE me_fmh; /**< File Mapping handle */
1345 /** Failed to update the meta page. Probably an I/O error. */
1346 #define MDB_FATAL_ERROR 0x80000000U
1347 /** Some fields are initialized. */
1348 #define MDB_ENV_ACTIVE 0x20000000U
1349 /** me_txkey is set */
1350 #define MDB_ENV_TXKEY 0x10000000U
1351 /** fdatasync is unreliable */
1352 #define MDB_FSYNCONLY 0x08000000U
1353 uint32_t me_flags; /**< @ref mdb_env */
1354 unsigned int me_psize; /**< DB page size, inited from me_os_psize */
1355 unsigned int me_os_psize; /**< OS page size, from #GET_PAGESIZE */
1356 unsigned int me_maxreaders; /**< size of the reader table */
1357 /** Max #MDB_txninfo.%mti_numreaders of interest to #mdb_env_close() */
1358 volatile int me_close_readers;
1359 MDB_dbi me_numdbs; /**< number of DBs opened */
1360 MDB_dbi me_maxdbs; /**< size of the DB table */
1361 MDB_PID_T me_pid; /**< process ID of this env */
1362 char *me_path; /**< path to the DB files */
1363 char *me_map; /**< the memory map of the data file */
1364 MDB_txninfo *me_txns; /**< the memory map of the lock file or NULL */
1365 MDB_meta *me_metas[NUM_METAS]; /**< pointers to the two meta pages */
1366 void *me_pbuf; /**< scratch area for DUPSORT put() */
1367 MDB_txn *me_txn; /**< current write transaction */
1368 MDB_txn *me_txn0; /**< prealloc'd write transaction */
1369 mdb_size_t me_mapsize; /**< size of the data memory map */
1370 off_t me_size; /**< current file size */
1371 pgno_t me_maxpg; /**< me_mapsize / me_psize */
1372 MDB_dbx *me_dbxs; /**< array of static DB info */
1373 uint16_t *me_dbflags; /**< array of flags from MDB_db.md_flags */
1374 unsigned int *me_dbiseqs; /**< array of dbi sequence numbers */
1375 pthread_key_t me_txkey; /**< thread-key for readers */
1376 txnid_t me_pgoldest; /**< ID of oldest reader last time we looked */
1377 MDB_pgstate me_pgstate; /**< state of old pages from freeDB */
1378 # define me_pglast me_pgstate.mf_pglast
1379 # define me_pghead me_pgstate.mf_pghead
1380 MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */
1381 /** IDL of pages that became unused in a write txn */
1382 MDB_IDL me_free_pgs;
1383 /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */
1384 MDB_ID2L me_dirty_list;
1385 /** Max number of freelist items that can fit in a single overflow page */
1387 /** Max size of a node on a page */
1388 unsigned int me_nodemax;
1389 #if !(MDB_MAXKEYSIZE)
1390 unsigned int me_maxkey; /**< max size of a key */
1392 int me_live_reader; /**< have liveness lock in reader table */
1394 int me_pidquery; /**< Used in OpenProcess */
1396 #ifdef MDB_USE_POSIX_MUTEX /* Posix mutexes reside in shared mem */
1397 # define me_rmutex me_txns->mti_rmutex /**< Shared reader lock */
1398 # define me_wmutex me_txns->mti_wmutex /**< Shared writer lock */
1400 mdb_mutex_t me_rmutex;
1401 mdb_mutex_t me_wmutex;
1404 MDB_ID3L me_rpages; /**< like #mt_rpages, but global to env */
1405 pthread_mutex_t me_rpmutex; /**< control access to #me_rpages */
1406 #define MDB_ERPAGE_SIZE 16384
1407 #define MDB_ERPAGE_MAX (MDB_ERPAGE_SIZE-1)
1408 unsigned int me_rpcheck;
1410 void *me_userctx; /**< User-settable context */
1411 MDB_assert_func *me_assert_func; /**< Callback for assertion failures */
1414 /** Nested transaction */
1415 typedef struct MDB_ntxn {
1416 MDB_txn mnt_txn; /**< the transaction */
1417 MDB_pgstate mnt_pgstate; /**< parent transaction's saved freestate */
1420 /** max number of pages to commit in one writev() call */
1421 #define MDB_COMMIT_PAGES 64
1422 #if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES
1423 #undef MDB_COMMIT_PAGES
1424 #define MDB_COMMIT_PAGES IOV_MAX
1427 /** max bytes to write in one call */
1428 #define MAX_WRITE (0x40000000U >> (sizeof(ssize_t) == 4))
1430 /** Check \b txn and \b dbi arguments to a function */
1431 #define TXN_DBI_EXIST(txn, dbi, validity) \
1432 ((txn) && (dbi)<(txn)->mt_numdbs && ((txn)->mt_dbflags[dbi] & (validity)))
1434 /** Check for misused \b dbi handles */
1435 #define TXN_DBI_CHANGED(txn, dbi) \
1436 ((txn)->mt_dbiseqs[dbi] != (txn)->mt_env->me_dbiseqs[dbi])
1438 static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp);
1439 static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp);
1440 static int mdb_page_touch(MDB_cursor *mc);
1442 #define MDB_END_NAMES {"committed", "empty-commit", "abort", "reset", \
1443 "reset-tmp", "fail-begin", "fail-beginchild"}
1445 /* mdb_txn_end operation number, for logging */
1446 MDB_END_COMMITTED, MDB_END_EMPTY_COMMIT, MDB_END_ABORT, MDB_END_RESET,
1447 MDB_END_RESET_TMP, MDB_END_FAIL_BEGIN, MDB_END_FAIL_BEGINCHILD
1449 #define MDB_END_OPMASK 0x0F /**< mask for #mdb_txn_end() operation number */
1450 #define MDB_END_UPDATE 0x10 /**< update env state (DBIs) */
1451 #define MDB_END_FREE 0x20 /**< free txn unless it is #MDB_env.%me_txn0 */
1452 #define MDB_END_SLOT MDB_NOTLS /**< release any reader slot if #MDB_NOTLS */
1453 static void mdb_txn_end(MDB_txn *txn, unsigned mode);
1455 static int mdb_page_get(MDB_cursor *mc, pgno_t pgno, MDB_page **mp, int *lvl);
1456 static int mdb_page_search_root(MDB_cursor *mc,
1457 MDB_val *key, int modify);
1458 #define MDB_PS_MODIFY 1
1459 #define MDB_PS_ROOTONLY 2
1460 #define MDB_PS_FIRST 4
1461 #define MDB_PS_LAST 8
1462 static int mdb_page_search(MDB_cursor *mc,
1463 MDB_val *key, int flags);
1464 static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst);
1466 #define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */
1467 static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
1468 pgno_t newpgno, unsigned int nflags);
1470 static int mdb_env_read_header(MDB_env *env, MDB_meta *meta);
1471 static MDB_meta *mdb_env_pick_meta(const MDB_env *env);
1472 static int mdb_env_write_meta(MDB_txn *txn);
1473 #ifdef MDB_USE_POSIX_MUTEX /* Drop unused excl arg */
1474 # define mdb_env_close0(env, excl) mdb_env_close1(env)
1476 static void mdb_env_close0(MDB_env *env, int excl);
1478 static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp);
1479 static int mdb_node_add(MDB_cursor *mc, indx_t indx,
1480 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags);
1481 static void mdb_node_del(MDB_cursor *mc, int ksize);
1482 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
1483 static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft);
1484 static int mdb_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data);
1485 static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
1486 static size_t mdb_branch_size(MDB_env *env, MDB_val *key);
1488 static int mdb_rebalance(MDB_cursor *mc);
1489 static int mdb_update_key(MDB_cursor *mc, MDB_val *key);
1491 static void mdb_cursor_pop(MDB_cursor *mc);
1492 static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp);
1494 static int mdb_cursor_del0(MDB_cursor *mc);
1495 static int mdb_del0(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, unsigned flags);
1496 static int mdb_cursor_sibling(MDB_cursor *mc, int move_right);
1497 static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1498 static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op);
1499 static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op,
1501 static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1502 static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data);
1504 static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx);
1505 static void mdb_xcursor_init0(MDB_cursor *mc);
1506 static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
1507 static void mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int force);
1509 static int mdb_drop0(MDB_cursor *mc, int subs);
1510 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
1511 static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead);
1514 static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
1517 /** Compare two items pointing at size_t's of unknown alignment. */
1518 #ifdef MISALIGNED_OK
1519 # define mdb_cmp_clong mdb_cmp_long
1521 # define mdb_cmp_clong mdb_cmp_cint
1524 /** True if we need #mdb_cmp_clong() instead of \b cmp for #MDB_INTEGERDUP */
1525 #define NEED_CMP_CLONG(cmp, ksize) \
1526 (UINT_MAX < MDB_SIZE_MAX && \
1527 (cmp) == mdb_cmp_int && (ksize) == sizeof(mdb_size_t))
1530 static SECURITY_DESCRIPTOR mdb_null_sd;
1531 static SECURITY_ATTRIBUTES mdb_all_sa;
1532 static int mdb_sec_inited;
1534 static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize);
1537 /** Return the library version info. */
1539 mdb_version(int *major, int *minor, int *patch)
1541 if (major) *major = MDB_VERSION_MAJOR;
1542 if (minor) *minor = MDB_VERSION_MINOR;
1543 if (patch) *patch = MDB_VERSION_PATCH;
1544 return MDB_VERSION_STRING;
1547 /** Table of descriptions for LMDB @ref errors */
1548 static char *const mdb_errstr[] = {
1549 "MDB_KEYEXIST: Key/data pair already exists",
1550 "MDB_NOTFOUND: No matching key/data pair found",
1551 "MDB_PAGE_NOTFOUND: Requested page not found",
1552 "MDB_CORRUPTED: Located page was wrong type",
1553 "MDB_PANIC: Update of meta page failed or environment had fatal error",
1554 "MDB_VERSION_MISMATCH: Database environment version mismatch",
1555 "MDB_INVALID: File is not an LMDB file",
1556 "MDB_MAP_FULL: Environment mapsize limit reached",
1557 "MDB_DBS_FULL: Environment maxdbs limit reached",
1558 "MDB_READERS_FULL: Environment maxreaders limit reached",
1559 "MDB_TLS_FULL: Thread-local storage keys full - too many environments open",
1560 "MDB_TXN_FULL: Transaction has too many dirty pages - transaction too big",
1561 "MDB_CURSOR_FULL: Internal error - cursor stack limit reached",
1562 "MDB_PAGE_FULL: Internal error - page has no more space",
1563 "MDB_MAP_RESIZED: Database contents grew beyond environment mapsize",
1564 "MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed",
1565 "MDB_BAD_RSLOT: Invalid reuse of reader locktable slot",
1566 "MDB_BAD_TXN: Transaction must abort, has a child, or is invalid",
1567 "MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size",
1568 "MDB_BAD_DBI: The specified DBI handle was closed/changed unexpectedly",
1569 "MDB_PROBLEM: Unexpected problem - txn should abort",
1573 mdb_strerror(int err)
1576 /** HACK: pad 4KB on stack over the buf. Return system msgs in buf.
1577 * This works as long as no function between the call to mdb_strerror
1578 * and the actual use of the message uses more than 4K of stack.
1580 #define MSGSIZE 1024
1581 #define PADSIZE 4096
1582 char buf[MSGSIZE+PADSIZE], *ptr = buf;
1586 return ("Successful return: 0");
1588 if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) {
1589 i = err - MDB_KEYEXIST;
1590 return mdb_errstr[i];
1594 /* These are the C-runtime error codes we use. The comment indicates
1595 * their numeric value, and the Win32 error they would correspond to
1596 * if the error actually came from a Win32 API. A major mess, we should
1597 * have used LMDB-specific error codes for everything.
1600 case ENOENT: /* 2, FILE_NOT_FOUND */
1601 case EIO: /* 5, ACCESS_DENIED */
1602 case ENOMEM: /* 12, INVALID_ACCESS */
1603 case EACCES: /* 13, INVALID_DATA */
1604 case EBUSY: /* 16, CURRENT_DIRECTORY */
1605 case EINVAL: /* 22, BAD_COMMAND */
1606 case ENOSPC: /* 28, OUT_OF_PAPER */
1607 return strerror(err);
1612 FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM |
1613 FORMAT_MESSAGE_IGNORE_INSERTS,
1614 NULL, err, 0, ptr, MSGSIZE, (va_list *)buf+MSGSIZE);
1617 return strerror(err);
1621 /** assert(3) variant in cursor context */
1622 #define mdb_cassert(mc, expr) mdb_assert0((mc)->mc_txn->mt_env, expr, #expr)
1623 /** assert(3) variant in transaction context */
1624 #define mdb_tassert(txn, expr) mdb_assert0((txn)->mt_env, expr, #expr)
1625 /** assert(3) variant in environment context */
1626 #define mdb_eassert(env, expr) mdb_assert0(env, expr, #expr)
1629 # define mdb_assert0(env, expr, expr_txt) ((expr) ? (void)0 : \
1630 mdb_assert_fail(env, expr_txt, mdb_func_, __FILE__, __LINE__))
1633 mdb_assert_fail(MDB_env *env, const char *expr_txt,
1634 const char *func, const char *file, int line)
1637 sprintf(buf, "%.100s:%d: Assertion '%.200s' failed in %.40s()",
1638 file, line, expr_txt, func);
1639 if (env->me_assert_func)
1640 env->me_assert_func(env, buf);
1641 fprintf(stderr, "%s\n", buf);
1645 # define mdb_assert0(env, expr, expr_txt) ((void) 0)
1649 /** Return the page number of \b mp which may be sub-page, for debug output */
1651 mdb_dbg_pgno(MDB_page *mp)
1654 COPY_PGNO(ret, mp->mp_pgno);
1658 /** Display a key in hexadecimal and return the address of the result.
1659 * @param[in] key the key to display
1660 * @param[in] buf the buffer to write into. Should always be #DKBUF.
1661 * @return The key in hexadecimal form.
1664 mdb_dkey(MDB_val *key, char *buf)
1667 unsigned char *c = key->mv_data;
1673 if (key->mv_size > DKBUF_MAXKEYSIZE)
1674 return "MDB_MAXKEYSIZE";
1675 /* may want to make this a dynamic check: if the key is mostly
1676 * printable characters, print it as-is instead of converting to hex.
1680 for (i=0; i<key->mv_size; i++)
1681 ptr += sprintf(ptr, "%02x", *c++);
1683 sprintf(buf, "%.*s", key->mv_size, key->mv_data);
1689 mdb_leafnode_type(MDB_node *n)
1691 static char *const tp[2][2] = {{"", ": DB"}, {": sub-page", ": sub-DB"}};
1692 return F_ISSET(n->mn_flags, F_BIGDATA) ? ": overflow page" :
1693 tp[F_ISSET(n->mn_flags, F_DUPDATA)][F_ISSET(n->mn_flags, F_SUBDATA)];
1696 /** Display all the keys in the page. */
1698 mdb_page_list(MDB_page *mp)
1700 pgno_t pgno = mdb_dbg_pgno(mp);
1701 const char *type, *state = (mp->mp_flags & P_DIRTY) ? ", dirty" : "";
1703 unsigned int i, nkeys, nsize, total = 0;
1707 switch (mp->mp_flags & (P_BRANCH|P_LEAF|P_LEAF2|P_META|P_OVERFLOW|P_SUBP)) {
1708 case P_BRANCH: type = "Branch page"; break;
1709 case P_LEAF: type = "Leaf page"; break;
1710 case P_LEAF|P_SUBP: type = "Sub-page"; break;
1711 case P_LEAF|P_LEAF2: type = "LEAF2 page"; break;
1712 case P_LEAF|P_LEAF2|P_SUBP: type = "LEAF2 sub-page"; break;
1714 fprintf(stderr, "Overflow page %"Y"u pages %u%s\n",
1715 pgno, mp->mp_pages, state);
1718 fprintf(stderr, "Meta-page %"Y"u txnid %"Y"u\n",
1719 pgno, ((MDB_meta *)METADATA(mp))->mm_txnid);
1722 fprintf(stderr, "Bad page %"Y"u flags 0x%u\n", pgno, mp->mp_flags);
1726 nkeys = NUMKEYS(mp);
1727 fprintf(stderr, "%s %"Y"u numkeys %d%s\n", type, pgno, nkeys, state);
1729 for (i=0; i<nkeys; i++) {
1730 if (IS_LEAF2(mp)) { /* LEAF2 pages have no mp_ptrs[] or node headers */
1731 key.mv_size = nsize = mp->mp_pad;
1732 key.mv_data = LEAF2KEY(mp, i, nsize);
1734 fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key));
1737 node = NODEPTR(mp, i);
1738 key.mv_size = node->mn_ksize;
1739 key.mv_data = node->mn_data;
1740 nsize = NODESIZE + key.mv_size;
1741 if (IS_BRANCH(mp)) {
1742 fprintf(stderr, "key %d: page %"Y"u, %s\n", i, NODEPGNO(node),
1746 if (F_ISSET(node->mn_flags, F_BIGDATA))
1747 nsize += sizeof(pgno_t);
1749 nsize += NODEDSZ(node);
1751 nsize += sizeof(indx_t);
1752 fprintf(stderr, "key %d: nsize %d, %s%s\n",
1753 i, nsize, DKEY(&key), mdb_leafnode_type(node));
1755 total = EVEN(total);
1757 fprintf(stderr, "Total: header %d + contents %d + unused %d\n",
1758 IS_LEAF2(mp) ? PAGEHDRSZ : PAGEBASE + mp->mp_lower, total, SIZELEFT(mp));
1762 mdb_cursor_chk(MDB_cursor *mc)
1768 if (!mc->mc_snum || !(mc->mc_flags & C_INITIALIZED)) return;
1769 for (i=0; i<mc->mc_top; i++) {
1771 node = NODEPTR(mp, mc->mc_ki[i]);
1772 if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno)
1775 if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i]))
1777 if (mc->mc_xcursor && (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
1778 node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
1779 if (((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA) &&
1780 mc->mc_xcursor->mx_cursor.mc_pg[0] != NODEDATA(node)) {
1788 /** Count all the pages in each DB and in the freelist
1789 * and make sure it matches the actual number of pages
1791 * All named DBs must be open for a correct count.
1793 static void mdb_audit(MDB_txn *txn)
1797 MDB_ID freecount, count;
1802 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
1803 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
1804 freecount += *(MDB_ID *)data.mv_data;
1805 mdb_tassert(txn, rc == MDB_NOTFOUND);
1808 for (i = 0; i<txn->mt_numdbs; i++) {
1810 if (!(txn->mt_dbflags[i] & DB_VALID))
1812 mdb_cursor_init(&mc, txn, i, &mx);
1813 if (txn->mt_dbs[i].md_root == P_INVALID)
1815 count += txn->mt_dbs[i].md_branch_pages +
1816 txn->mt_dbs[i].md_leaf_pages +
1817 txn->mt_dbs[i].md_overflow_pages;
1818 if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) {
1819 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST);
1820 for (; rc == MDB_SUCCESS; rc = mdb_cursor_sibling(&mc, 1)) {
1823 mp = mc.mc_pg[mc.mc_top];
1824 for (j=0; j<NUMKEYS(mp); j++) {
1825 MDB_node *leaf = NODEPTR(mp, j);
1826 if (leaf->mn_flags & F_SUBDATA) {
1828 memcpy(&db, NODEDATA(leaf), sizeof(db));
1829 count += db.md_branch_pages + db.md_leaf_pages +
1830 db.md_overflow_pages;
1834 mdb_tassert(txn, rc == MDB_NOTFOUND);
1837 if (freecount + count + NUM_METAS != txn->mt_next_pgno) {
1838 fprintf(stderr, "audit: %"Y"u freecount: %"Y"u count: %"Y"u total: %"Y"u next_pgno: %"Y"u\n",
1839 txn->mt_txnid, freecount, count+NUM_METAS,
1840 freecount+count+NUM_METAS, txn->mt_next_pgno);
1846 mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1848 return txn->mt_dbxs[dbi].md_cmp(a, b);
1852 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
1854 MDB_cmp_func *dcmp = txn->mt_dbxs[dbi].md_dcmp;
1855 if (NEED_CMP_CLONG(dcmp, a->mv_size))
1856 dcmp = mdb_cmp_clong;
1860 /** Allocate memory for a page.
1861 * Re-use old malloc'd pages first for singletons, otherwise just malloc.
1864 mdb_page_malloc(MDB_txn *txn, unsigned num)
1866 MDB_env *env = txn->mt_env;
1867 MDB_page *ret = env->me_dpages;
1868 size_t psize = env->me_psize, sz = psize, off;
1869 /* For ! #MDB_NOMEMINIT, psize counts how much to init.
1870 * For a single page alloc, we init everything after the page header.
1871 * For multi-page, we init the final page; if the caller needed that
1872 * many pages they will be filling in at least up to the last page.
1876 VGMEMP_ALLOC(env, ret, sz);
1877 VGMEMP_DEFINED(ret, sizeof(ret->mp_next));
1878 env->me_dpages = ret->mp_next;
1881 psize -= off = PAGEHDRSZ;
1886 if ((ret = malloc(sz)) != NULL) {
1887 VGMEMP_ALLOC(env, ret, sz);
1888 if (!(env->me_flags & MDB_NOMEMINIT)) {
1889 memset((char *)ret + off, 0, psize);
1893 txn->mt_flags |= MDB_TXN_ERROR;
1897 /** Free a single page.
1898 * Saves single pages to a list, for future reuse.
1899 * (This is not used for multi-page overflow pages.)
1902 mdb_page_free(MDB_env *env, MDB_page *mp)
1904 mp->mp_next = env->me_dpages;
1905 VGMEMP_FREE(env, mp);
1906 env->me_dpages = mp;
1909 /** Free a dirty page */
1911 mdb_dpage_free(MDB_env *env, MDB_page *dp)
1913 if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) {
1914 mdb_page_free(env, dp);
1916 /* large pages just get freed directly */
1917 VGMEMP_FREE(env, dp);
1922 /** Return all dirty pages to dpage list */
1924 mdb_dlist_free(MDB_txn *txn)
1926 MDB_env *env = txn->mt_env;
1927 MDB_ID2L dl = txn->mt_u.dirty_list;
1928 unsigned i, n = dl[0].mid;
1930 for (i = 1; i <= n; i++) {
1931 mdb_dpage_free(env, dl[i].mptr);
1938 mdb_page_unref(MDB_txn *txn, MDB_page *mp)
1941 MDB_ID3L tl = txn->mt_rpages;
1943 if (mp->mp_flags & (P_SUBP|P_DIRTY))
1945 rem = mp->mp_pgno & (MDB_RPAGE_CHUNK-1);
1946 pgno = mp->mp_pgno ^ rem;
1947 x = mdb_mid3l_search(tl, pgno);
1948 if (x != tl[0].mid && tl[x+1].mid == mp->mp_pgno)
1953 #define MDB_PAGE_UNREF(txn, mp) mdb_page_unref(txn, mp)
1956 mdb_cursor_unref(MDB_cursor *mc)
1959 if (!mc->mc_snum || !mc->mc_pg[0] || IS_SUBP(mc->mc_pg[0]))
1961 for (i=0; i<mc->mc_snum; i++)
1962 mdb_page_unref(mc->mc_txn, mc->mc_pg[i]);
1964 mdb_page_unref(mc->mc_txn, mc->mc_ovpg);
1967 mc->mc_snum = mc->mc_top = 0;
1968 mc->mc_pg[0] = NULL;
1969 mc->mc_flags &= ~C_INITIALIZED;
1971 #define MDB_CURSOR_UNREF(mc, force) \
1972 (((force) || ((mc)->mc_flags & C_INITIALIZED)) \
1973 ? mdb_cursor_unref(mc) \
1977 #define MDB_PAGE_UNREF(txn, mp)
1978 #define MDB_CURSOR_UNREF(mc, force) ((void)0)
1979 #endif /* MDB_VL32 */
1981 /** Loosen or free a single page.
1982 * Saves single pages to a list for future reuse
1983 * in this same txn. It has been pulled from the freeDB
1984 * and already resides on the dirty list, but has been
1985 * deleted. Use these pages first before pulling again
1988 * If the page wasn't dirtied in this txn, just add it
1989 * to this txn's free list.
1992 mdb_page_loose(MDB_cursor *mc, MDB_page *mp)
1995 pgno_t pgno = mp->mp_pgno;
1996 MDB_txn *txn = mc->mc_txn;
1998 if ((mp->mp_flags & P_DIRTY) && mc->mc_dbi != FREE_DBI) {
1999 if (txn->mt_parent) {
2000 MDB_ID2 *dl = txn->mt_u.dirty_list;
2001 /* If txn has a parent, make sure the page is in our
2005 unsigned x = mdb_mid2l_search(dl, pgno);
2006 if (x <= dl[0].mid && dl[x].mid == pgno) {
2007 if (mp != dl[x].mptr) { /* bad cursor? */
2008 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
2009 txn->mt_flags |= MDB_TXN_ERROR;
2017 /* no parent txn, so it's just ours */
2022 DPRINTF(("loosen db %d page %"Y"u", DDBI(mc),
2024 NEXT_LOOSE_PAGE(mp) = txn->mt_loose_pgs;
2025 txn->mt_loose_pgs = mp;
2026 txn->mt_loose_count++;
2027 mp->mp_flags |= P_LOOSE;
2029 int rc = mdb_midl_append(&txn->mt_free_pgs, pgno);
2037 /** Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn.
2038 * @param[in] mc A cursor handle for the current operation.
2039 * @param[in] pflags Flags of the pages to update:
2040 * P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it.
2041 * @param[in] all No shortcuts. Needed except after a full #mdb_page_flush().
2042 * @return 0 on success, non-zero on failure.
2045 mdb_pages_xkeep(MDB_cursor *mc, unsigned pflags, int all)
2047 enum { Mask = P_SUBP|P_DIRTY|P_LOOSE|P_KEEP };
2048 MDB_txn *txn = mc->mc_txn;
2049 MDB_cursor *m3, *m0 = mc;
2054 int rc = MDB_SUCCESS, level;
2056 /* Mark pages seen by cursors */
2057 if (mc->mc_flags & C_UNTRACK)
2058 mc = NULL; /* will find mc in mt_cursors */
2059 for (i = txn->mt_numdbs;; mc = txn->mt_cursors[--i]) {
2060 for (; mc; mc=mc->mc_next) {
2061 if (!(mc->mc_flags & C_INITIALIZED))
2063 for (m3 = mc;; m3 = &mx->mx_cursor) {
2065 for (j=0; j<m3->mc_snum; j++) {
2067 if ((mp->mp_flags & Mask) == pflags)
2068 mp->mp_flags ^= P_KEEP;
2070 mx = m3->mc_xcursor;
2071 /* Proceed to mx if it is at a sub-database */
2072 if (! (mx && (mx->mx_cursor.mc_flags & C_INITIALIZED)))
2074 if (! (mp && (mp->mp_flags & P_LEAF)))
2076 leaf = NODEPTR(mp, m3->mc_ki[j-1]);
2077 if (!(leaf->mn_flags & F_SUBDATA))
2086 /* Mark dirty root pages */
2087 for (i=0; i<txn->mt_numdbs; i++) {
2088 if (txn->mt_dbflags[i] & DB_DIRTY) {
2089 pgno_t pgno = txn->mt_dbs[i].md_root;
2090 if (pgno == P_INVALID)
2092 if ((rc = mdb_page_get(m0, pgno, &dp, &level)) != MDB_SUCCESS)
2094 if ((dp->mp_flags & Mask) == pflags && level <= 1)
2095 dp->mp_flags ^= P_KEEP;
2103 static int mdb_page_flush(MDB_txn *txn, int keep);
2105 /** Spill pages from the dirty list back to disk.
2106 * This is intended to prevent running into #MDB_TXN_FULL situations,
2107 * but note that they may still occur in a few cases:
2108 * 1) our estimate of the txn size could be too small. Currently this
2109 * seems unlikely, except with a large number of #MDB_MULTIPLE items.
2110 * 2) child txns may run out of space if their parents dirtied a
2111 * lot of pages and never spilled them. TODO: we probably should do
2112 * a preemptive spill during #mdb_txn_begin() of a child txn, if
2113 * the parent's dirty_room is below a given threshold.
2115 * Otherwise, if not using nested txns, it is expected that apps will
2116 * not run into #MDB_TXN_FULL any more. The pages are flushed to disk
2117 * the same way as for a txn commit, e.g. their P_DIRTY flag is cleared.
2118 * If the txn never references them again, they can be left alone.
2119 * If the txn only reads them, they can be used without any fuss.
2120 * If the txn writes them again, they can be dirtied immediately without
2121 * going thru all of the work of #mdb_page_touch(). Such references are
2122 * handled by #mdb_page_unspill().
2124 * Also note, we never spill DB root pages, nor pages of active cursors,
2125 * because we'll need these back again soon anyway. And in nested txns,
2126 * we can't spill a page in a child txn if it was already spilled in a
2127 * parent txn. That would alter the parent txns' data even though
2128 * the child hasn't committed yet, and we'd have no way to undo it if
2129 * the child aborted.
2131 * @param[in] m0 cursor A cursor handle identifying the transaction and
2132 * database for which we are checking space.
2133 * @param[in] key For a put operation, the key being stored.
2134 * @param[in] data For a put operation, the data being stored.
2135 * @return 0 on success, non-zero on failure.
2138 mdb_page_spill(MDB_cursor *m0, MDB_val *key, MDB_val *data)
2140 MDB_txn *txn = m0->mc_txn;
2142 MDB_ID2L dl = txn->mt_u.dirty_list;
2143 unsigned int i, j, need;
2146 if (m0->mc_flags & C_SUB)
2149 /* Estimate how much space this op will take */
2150 i = m0->mc_db->md_depth;
2151 /* Named DBs also dirty the main DB */
2152 if (m0->mc_dbi >= CORE_DBS)
2153 i += txn->mt_dbs[MAIN_DBI].md_depth;
2154 /* For puts, roughly factor in the key+data size */
2156 i += (LEAFSIZE(key, data) + txn->mt_env->me_psize) / txn->mt_env->me_psize;
2157 i += i; /* double it for good measure */
2160 if (txn->mt_dirty_room > i)
2163 if (!txn->mt_spill_pgs) {
2164 txn->mt_spill_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX);
2165 if (!txn->mt_spill_pgs)
2168 /* purge deleted slots */
2169 MDB_IDL sl = txn->mt_spill_pgs;
2170 unsigned int num = sl[0];
2172 for (i=1; i<=num; i++) {
2179 /* Preserve pages which may soon be dirtied again */
2180 if ((rc = mdb_pages_xkeep(m0, P_DIRTY, 1)) != MDB_SUCCESS)
2183 /* Less aggressive spill - we originally spilled the entire dirty list,
2184 * with a few exceptions for cursor pages and DB root pages. But this
2185 * turns out to be a lot of wasted effort because in a large txn many
2186 * of those pages will need to be used again. So now we spill only 1/8th
2187 * of the dirty pages. Testing revealed this to be a good tradeoff,
2188 * better than 1/2, 1/4, or 1/10.
2190 if (need < MDB_IDL_UM_MAX / 8)
2191 need = MDB_IDL_UM_MAX / 8;
2193 /* Save the page IDs of all the pages we're flushing */
2194 /* flush from the tail forward, this saves a lot of shifting later on. */
2195 for (i=dl[0].mid; i && need; i--) {
2196 MDB_ID pn = dl[i].mid << 1;
2198 if (dp->mp_flags & (P_LOOSE|P_KEEP))
2200 /* Can't spill twice, make sure it's not already in a parent's
2203 if (txn->mt_parent) {
2205 for (tx2 = txn->mt_parent; tx2; tx2 = tx2->mt_parent) {
2206 if (tx2->mt_spill_pgs) {
2207 j = mdb_midl_search(tx2->mt_spill_pgs, pn);
2208 if (j <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[j] == pn) {
2209 dp->mp_flags |= P_KEEP;
2217 if ((rc = mdb_midl_append(&txn->mt_spill_pgs, pn)))
2221 mdb_midl_sort(txn->mt_spill_pgs);
2223 /* Flush the spilled part of dirty list */
2224 if ((rc = mdb_page_flush(txn, i)) != MDB_SUCCESS)
2227 /* Reset any dirty pages we kept that page_flush didn't see */
2228 rc = mdb_pages_xkeep(m0, P_DIRTY|P_KEEP, i);
2231 txn->mt_flags |= rc ? MDB_TXN_ERROR : MDB_TXN_SPILLS;
2235 /** Find oldest txnid still referenced. Expects txn->mt_txnid > 0. */
2237 mdb_find_oldest(MDB_txn *txn)
2240 txnid_t mr, oldest = txn->mt_txnid - 1;
2241 if (txn->mt_env->me_txns) {
2242 MDB_reader *r = txn->mt_env->me_txns->mti_readers;
2243 for (i = txn->mt_env->me_txns->mti_numreaders; --i >= 0; ) {
2254 /** Add a page to the txn's dirty list */
2256 mdb_page_dirty(MDB_txn *txn, MDB_page *mp)
2259 int rc, (*insert)(MDB_ID2L, MDB_ID2 *);
2261 if (txn->mt_flags & MDB_TXN_WRITEMAP) {
2262 insert = mdb_mid2l_append;
2264 insert = mdb_mid2l_insert;
2266 mid.mid = mp->mp_pgno;
2268 rc = insert(txn->mt_u.dirty_list, &mid);
2269 mdb_tassert(txn, rc == 0);
2270 txn->mt_dirty_room--;
2273 /** Allocate page numbers and memory for writing. Maintain me_pglast,
2274 * me_pghead and mt_next_pgno.
2276 * If there are free pages available from older transactions, they
2277 * are re-used first. Otherwise allocate a new page at mt_next_pgno.
2278 * Do not modify the freedB, just merge freeDB records into me_pghead[]
2279 * and move me_pglast to say which records were consumed. Only this
2280 * function can create me_pghead and move me_pglast/mt_next_pgno.
2281 * When #MDB_DEVEL & 2, it is not affected by #mdb_freelist_save(): it
2282 * then uses the transaction's original snapshot of the freeDB.
2283 * @param[in] mc cursor A cursor handle identifying the transaction and
2284 * database for which we are allocating.
2285 * @param[in] num the number of pages to allocate.
2286 * @param[out] mp Address of the allocated page(s). Requests for multiple pages
2287 * will always be satisfied by a single contiguous chunk of memory.
2288 * @return 0 on success, non-zero on failure.
2291 mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp)
2293 #ifdef MDB_PARANOID /* Seems like we can ignore this now */
2294 /* Get at most <Max_retries> more freeDB records once me_pghead
2295 * has enough pages. If not enough, use new pages from the map.
2296 * If <Paranoid> and mc is updating the freeDB, only get new
2297 * records if me_pghead is empty. Then the freelist cannot play
2298 * catch-up with itself by growing while trying to save it.
2300 enum { Paranoid = 1, Max_retries = 500 };
2302 enum { Paranoid = 0, Max_retries = INT_MAX /*infinite*/ };
2304 int rc, retry = num * 60;
2305 MDB_txn *txn = mc->mc_txn;
2306 MDB_env *env = txn->mt_env;
2307 pgno_t pgno, *mop = env->me_pghead;
2308 unsigned i, j, mop_len = mop ? mop[0] : 0, n2 = num-1;
2310 txnid_t oldest = 0, last;
2315 /* If there are any loose pages, just use them */
2316 if (num == 1 && txn->mt_loose_pgs) {
2317 np = txn->mt_loose_pgs;
2318 txn->mt_loose_pgs = NEXT_LOOSE_PAGE(np);
2319 txn->mt_loose_count--;
2320 DPRINTF(("db %d use loose page %"Y"u", DDBI(mc),
2328 /* If our dirty list is already full, we can't do anything */
2329 if (txn->mt_dirty_room == 0) {
2334 for (op = MDB_FIRST;; op = MDB_NEXT) {
2339 /* Seek a big enough contiguous page range. Prefer
2340 * pages at the tail, just truncating the list.
2346 if (mop[i-n2] == pgno+n2)
2353 if (op == MDB_FIRST) { /* 1st iteration */
2354 /* Prepare to fetch more and coalesce */
2355 last = env->me_pglast;
2356 oldest = env->me_pgoldest;
2357 mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
2358 #if (MDB_DEVEL) & 2 /* "& 2" so MDB_DEVEL=1 won't hide bugs breaking freeDB */
2359 /* Use original snapshot. TODO: Should need less care in code
2360 * which modifies the database. Maybe we can delete some code?
2362 m2.mc_flags |= C_ORIG_RDONLY;
2363 m2.mc_db = &env->me_metas[(txn->mt_txnid-1) & 1]->mm_dbs[FREE_DBI];
2364 m2.mc_dbflag = (unsigned char *)""; /* probably unnecessary */
2368 key.mv_data = &last; /* will look up last+1 */
2369 key.mv_size = sizeof(last);
2371 if (Paranoid && mc->mc_dbi == FREE_DBI)
2374 if (Paranoid && retry < 0 && mop_len)
2378 /* Do not fetch more if the record will be too recent */
2379 if (oldest <= last) {
2381 oldest = mdb_find_oldest(txn);
2382 env->me_pgoldest = oldest;
2388 rc = mdb_cursor_get(&m2, &key, NULL, op);
2390 if (rc == MDB_NOTFOUND)
2394 last = *(txnid_t*)key.mv_data;
2395 if (oldest <= last) {
2397 oldest = mdb_find_oldest(txn);
2398 env->me_pgoldest = oldest;
2404 np = m2.mc_pg[m2.mc_top];
2405 leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
2406 if ((rc = mdb_node_read(&m2, leaf, &data)) != MDB_SUCCESS)
2409 idl = (MDB_ID *) data.mv_data;
2412 if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {
2417 if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
2419 mop = env->me_pghead;
2421 env->me_pglast = last;
2423 DPRINTF(("IDL read txn %"Y"u root %"Y"u num %u",
2424 last, txn->mt_dbs[FREE_DBI].md_root, i));
2426 DPRINTF(("IDL %"Y"u", idl[j]));
2428 /* Merge in descending sorted order */
2429 mdb_midl_xmerge(mop, idl);
2433 /* Use new pages from the map when nothing suitable in the freeDB */
2435 pgno = txn->mt_next_pgno;
2436 if (pgno + num >= env->me_maxpg) {
2437 DPUTS("DB size maxed out");
2441 #if defined(_WIN32) && !defined(MDB_VL32)
2442 if (!(env->me_flags & MDB_RDONLY)) {
2444 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
2445 p = VirtualAlloc(p, env->me_psize * num, MEM_COMMIT,
2446 (env->me_flags & MDB_WRITEMAP) ? PAGE_READWRITE:
2449 DPUTS("VirtualAlloc failed");
2457 if (env->me_flags & MDB_WRITEMAP) {
2458 np = (MDB_page *)(env->me_map + env->me_psize * pgno);
2460 if (!(np = mdb_page_malloc(txn, num))) {
2466 mop[0] = mop_len -= num;
2467 /* Move any stragglers down */
2468 for (j = i-num; j < mop_len; )
2469 mop[++j] = mop[++i];
2471 txn->mt_next_pgno = pgno + num;
2474 mdb_page_dirty(txn, np);
2480 txn->mt_flags |= MDB_TXN_ERROR;
2484 /** Copy the used portions of a non-overflow page.
2485 * @param[in] dst page to copy into
2486 * @param[in] src page to copy from
2487 * @param[in] psize size of a page
2490 mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize)
2492 enum { Align = sizeof(pgno_t) };
2493 indx_t upper = src->mp_upper, lower = src->mp_lower, unused = upper-lower;
2495 /* If page isn't full, just copy the used portion. Adjust
2496 * alignment so memcpy may copy words instead of bytes.
2498 if ((unused &= -Align) && !IS_LEAF2(src)) {
2499 upper = (upper + PAGEBASE) & -Align;
2500 memcpy(dst, src, (lower + PAGEBASE + (Align-1)) & -Align);
2501 memcpy((pgno_t *)((char *)dst+upper), (pgno_t *)((char *)src+upper),
2504 memcpy(dst, src, psize - unused);
2508 /** Pull a page off the txn's spill list, if present.
2509 * If a page being referenced was spilled to disk in this txn, bring
2510 * it back and make it dirty/writable again.
2511 * @param[in] txn the transaction handle.
2512 * @param[in] mp the page being referenced. It must not be dirty.
2513 * @param[out] ret the writable page, if any. ret is unchanged if
2514 * mp wasn't spilled.
2517 mdb_page_unspill(MDB_txn *txn, MDB_page *mp, MDB_page **ret)
2519 MDB_env *env = txn->mt_env;
2522 pgno_t pgno = mp->mp_pgno, pn = pgno << 1;
2524 for (tx2 = txn; tx2; tx2=tx2->mt_parent) {
2525 if (!tx2->mt_spill_pgs)
2527 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
2528 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
2531 if (txn->mt_dirty_room == 0)
2532 return MDB_TXN_FULL;
2533 if (IS_OVERFLOW(mp))
2537 if (env->me_flags & MDB_WRITEMAP) {
2540 np = mdb_page_malloc(txn, num);
2544 memcpy(np, mp, num * env->me_psize);
2546 mdb_page_copy(np, mp, env->me_psize);
2549 /* If in current txn, this page is no longer spilled.
2550 * If it happens to be the last page, truncate the spill list.
2551 * Otherwise mark it as deleted by setting the LSB.
2553 if (x == txn->mt_spill_pgs[0])
2554 txn->mt_spill_pgs[0]--;
2556 txn->mt_spill_pgs[x] |= 1;
2557 } /* otherwise, if belonging to a parent txn, the
2558 * page remains spilled until child commits
2561 mdb_page_dirty(txn, np);
2562 np->mp_flags |= P_DIRTY;
2570 /** Touch a page: make it dirty and re-insert into tree with updated pgno.
2571 * @param[in] mc cursor pointing to the page to be touched
2572 * @return 0 on success, non-zero on failure.
2575 mdb_page_touch(MDB_cursor *mc)
2577 MDB_page *mp = mc->mc_pg[mc->mc_top], *np;
2578 MDB_txn *txn = mc->mc_txn;
2579 MDB_cursor *m2, *m3;
2583 if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
2584 if (txn->mt_flags & MDB_TXN_SPILLS) {
2586 rc = mdb_page_unspill(txn, mp, &np);
2592 if ((rc = mdb_midl_need(&txn->mt_free_pgs, 1)) ||
2593 (rc = mdb_page_alloc(mc, 1, &np)))
2596 DPRINTF(("touched db %d page %"Y"u -> %"Y"u", DDBI(mc),
2597 mp->mp_pgno, pgno));
2598 mdb_cassert(mc, mp->mp_pgno != pgno);
2599 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
2600 /* Update the parent page, if any, to point to the new page */
2602 MDB_page *parent = mc->mc_pg[mc->mc_top-1];
2603 MDB_node *node = NODEPTR(parent, mc->mc_ki[mc->mc_top-1]);
2604 SETPGNO(node, pgno);
2606 mc->mc_db->md_root = pgno;
2608 } else if (txn->mt_parent && !IS_SUBP(mp)) {
2609 MDB_ID2 mid, *dl = txn->mt_u.dirty_list;
2611 /* If txn has a parent, make sure the page is in our
2615 unsigned x = mdb_mid2l_search(dl, pgno);
2616 if (x <= dl[0].mid && dl[x].mid == pgno) {
2617 if (mp != dl[x].mptr) { /* bad cursor? */
2618 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
2619 txn->mt_flags |= MDB_TXN_ERROR;
2625 mdb_cassert(mc, dl[0].mid < MDB_IDL_UM_MAX);
2627 np = mdb_page_malloc(txn, 1);
2632 rc = mdb_mid2l_insert(dl, &mid);
2633 mdb_cassert(mc, rc == 0);
2638 mdb_page_copy(np, mp, txn->mt_env->me_psize);
2640 np->mp_flags |= P_DIRTY;
2643 /* Adjust cursors pointing to mp */
2644 mc->mc_pg[mc->mc_top] = np;
2645 m2 = txn->mt_cursors[mc->mc_dbi];
2646 if (mc->mc_flags & C_SUB) {
2647 for (; m2; m2=m2->mc_next) {
2648 m3 = &m2->mc_xcursor->mx_cursor;
2649 if (m3->mc_snum < mc->mc_snum) continue;
2650 if (m3->mc_pg[mc->mc_top] == mp)
2651 m3->mc_pg[mc->mc_top] = np;
2654 for (; m2; m2=m2->mc_next) {
2655 if (m2->mc_snum < mc->mc_snum) continue;
2656 if (m2 == mc) continue;
2657 if (m2->mc_pg[mc->mc_top] == mp) {
2658 m2->mc_pg[mc->mc_top] = np;
2659 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
2661 (m2->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
2663 MDB_node *leaf = NODEPTR(np, m2->mc_ki[mc->mc_top]);
2664 if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
2665 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
2670 MDB_PAGE_UNREF(mc->mc_txn, mp);
2674 txn->mt_flags |= MDB_TXN_ERROR;
2679 mdb_env_sync0(MDB_env *env, int force, pgno_t numpgs)
2682 if (env->me_flags & MDB_RDONLY)
2684 if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) {
2685 if (env->me_flags & MDB_WRITEMAP) {
2686 int flags = ((env->me_flags & MDB_MAPASYNC) && !force)
2687 ? MS_ASYNC : MS_SYNC;
2688 if (MDB_MSYNC(env->me_map, env->me_psize * numpgs, flags))
2691 else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd))
2695 #ifdef BROKEN_FDATASYNC
2696 if (env->me_flags & MDB_FSYNCONLY) {
2697 if (fsync(env->me_fd))
2701 if (MDB_FDATASYNC(env->me_fd))
2709 mdb_env_sync(MDB_env *env, int force)
2711 MDB_meta *m = mdb_env_pick_meta(env);
2712 return mdb_env_sync0(env, force, m->mm_last_pg+1);
2715 /** Back up parent txn's cursors, then grab the originals for tracking */
2717 mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
2719 MDB_cursor *mc, *bk;
2724 for (i = src->mt_numdbs; --i >= 0; ) {
2725 if ((mc = src->mt_cursors[i]) != NULL) {
2726 size = sizeof(MDB_cursor);
2728 size += sizeof(MDB_xcursor);
2729 for (; mc; mc = bk->mc_next) {
2735 mc->mc_db = &dst->mt_dbs[i];
2736 /* Kill pointers into src to reduce abuse: The
2737 * user may not use mc until dst ends. But we need a valid
2738 * txn pointer here for cursor fixups to keep working.
2741 mc->mc_dbflag = &dst->mt_dbflags[i];
2742 if ((mx = mc->mc_xcursor) != NULL) {
2743 *(MDB_xcursor *)(bk+1) = *mx;
2744 mx->mx_cursor.mc_txn = dst;
2746 mc->mc_next = dst->mt_cursors[i];
2747 dst->mt_cursors[i] = mc;
2754 /** Close this write txn's cursors, give parent txn's cursors back to parent.
2755 * @param[in] txn the transaction handle.
2756 * @param[in] merge true to keep changes to parent cursors, false to revert.
2757 * @return 0 on success, non-zero on failure.
2760 mdb_cursors_close(MDB_txn *txn, unsigned merge)
2762 MDB_cursor **cursors = txn->mt_cursors, *mc, *next, *bk;
2766 for (i = txn->mt_numdbs; --i >= 0; ) {
2767 for (mc = cursors[i]; mc; mc = next) {
2769 if ((bk = mc->mc_backup) != NULL) {
2771 /* Commit changes to parent txn */
2772 mc->mc_next = bk->mc_next;
2773 mc->mc_backup = bk->mc_backup;
2774 mc->mc_txn = bk->mc_txn;
2775 mc->mc_db = bk->mc_db;
2776 mc->mc_dbflag = bk->mc_dbflag;
2777 if ((mx = mc->mc_xcursor) != NULL)
2778 mx->mx_cursor.mc_txn = bk->mc_txn;
2780 /* Abort nested txn */
2782 if ((mx = mc->mc_xcursor) != NULL)
2783 *mx = *(MDB_xcursor *)(bk+1);
2787 /* Only malloced cursors are permanently tracked. */
2794 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2800 Pidset = F_SETLK, Pidcheck = F_GETLK
2804 /** Set or check a pid lock. Set returns 0 on success.
2805 * Check returns 0 if the process is certainly dead, nonzero if it may
2806 * be alive (the lock exists or an error happened so we do not know).
2808 * On Windows Pidset is a no-op, we merely check for the existence
2809 * of the process with the given pid. On POSIX we use a single byte
2810 * lock on the lockfile, set at an offset equal to the pid.
2813 mdb_reader_pid(MDB_env *env, enum Pidlock_op op, MDB_PID_T pid)
2815 #if !(MDB_PIDLOCK) /* Currently the same as defined(_WIN32) */
2818 if (op == Pidcheck) {
2819 h = OpenProcess(env->me_pidquery, FALSE, pid);
2820 /* No documented "no such process" code, but other program use this: */
2822 return ErrCode() != ERROR_INVALID_PARAMETER;
2823 /* A process exists until all handles to it close. Has it exited? */
2824 ret = WaitForSingleObject(h, 0) != 0;
2831 struct flock lock_info;
2832 memset(&lock_info, 0, sizeof(lock_info));
2833 lock_info.l_type = F_WRLCK;
2834 lock_info.l_whence = SEEK_SET;
2835 lock_info.l_start = pid;
2836 lock_info.l_len = 1;
2837 if ((rc = fcntl(env->me_lfd, op, &lock_info)) == 0) {
2838 if (op == F_GETLK && lock_info.l_type != F_UNLCK)
2840 } else if ((rc = ErrCode()) == EINTR) {
2848 /** Common code for #mdb_txn_begin() and #mdb_txn_renew().
2849 * @param[in] txn the transaction handle to initialize
2850 * @return 0 on success, non-zero on failure.
2853 mdb_txn_renew0(MDB_txn *txn)
2855 MDB_env *env = txn->mt_env;
2856 MDB_txninfo *ti = env->me_txns;
2858 unsigned int i, nr, flags = txn->mt_flags;
2860 int rc, new_notls = 0;
2862 if ((flags &= MDB_TXN_RDONLY) != 0) {
2864 meta = mdb_env_pick_meta(env);
2865 txn->mt_txnid = meta->mm_txnid;
2866 txn->mt_u.reader = NULL;
2868 MDB_reader *r = (env->me_flags & MDB_NOTLS) ? txn->mt_u.reader :
2869 pthread_getspecific(env->me_txkey);
2871 if (r->mr_pid != env->me_pid || r->mr_txnid != (txnid_t)-1)
2872 return MDB_BAD_RSLOT;
2874 MDB_PID_T pid = env->me_pid;
2875 MDB_THR_T tid = pthread_self();
2876 mdb_mutexref_t rmutex = env->me_rmutex;
2878 if (!env->me_live_reader) {
2879 rc = mdb_reader_pid(env, Pidset, pid);
2882 env->me_live_reader = 1;
2885 if (LOCK_MUTEX(rc, env, rmutex))
2887 nr = ti->mti_numreaders;
2888 for (i=0; i<nr; i++)
2889 if (ti->mti_readers[i].mr_pid == 0)
2891 if (i == env->me_maxreaders) {
2892 UNLOCK_MUTEX(rmutex);
2893 return MDB_READERS_FULL;
2895 r = &ti->mti_readers[i];
2896 /* Claim the reader slot, carefully since other code
2897 * uses the reader table un-mutexed: First reset the
2898 * slot, next publish it in mti_numreaders. After
2899 * that, it is safe for mdb_env_close() to touch it.
2900 * When it will be closed, we can finally claim it.
2903 r->mr_txnid = (txnid_t)-1;
2906 ti->mti_numreaders = ++nr;
2907 env->me_close_readers = nr;
2909 UNLOCK_MUTEX(rmutex);
2911 new_notls = (env->me_flags & MDB_NOTLS);
2912 if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
2917 do /* LY: Retry on a race, ITS#7970. */
2918 r->mr_txnid = ti->mti_txnid;
2919 while(r->mr_txnid != ti->mti_txnid);
2920 txn->mt_txnid = r->mr_txnid;
2921 txn->mt_u.reader = r;
2922 meta = env->me_metas[txn->mt_txnid & 1];
2926 /* Not yet touching txn == env->me_txn0, it may be active */
2928 if (LOCK_MUTEX(rc, env, env->me_wmutex))
2930 txn->mt_txnid = ti->mti_txnid;
2931 meta = env->me_metas[txn->mt_txnid & 1];
2933 meta = mdb_env_pick_meta(env);
2934 txn->mt_txnid = meta->mm_txnid;
2938 if (txn->mt_txnid == mdb_debug_start)
2941 txn->mt_child = NULL;
2942 txn->mt_loose_pgs = NULL;
2943 txn->mt_loose_count = 0;
2944 txn->mt_dirty_room = MDB_IDL_UM_MAX;
2945 txn->mt_u.dirty_list = env->me_dirty_list;
2946 txn->mt_u.dirty_list[0].mid = 0;
2947 txn->mt_free_pgs = env->me_free_pgs;
2948 txn->mt_free_pgs[0] = 0;
2949 txn->mt_spill_pgs = NULL;
2951 memcpy(txn->mt_dbiseqs, env->me_dbiseqs, env->me_maxdbs * sizeof(unsigned int));
2954 /* Copy the DB info and flags */
2955 memcpy(txn->mt_dbs, meta->mm_dbs, CORE_DBS * sizeof(MDB_db));
2957 /* Moved to here to avoid a data race in read TXNs */
2958 txn->mt_next_pgno = meta->mm_last_pg+1;
2960 txn->mt_last_pgno = txn->mt_next_pgno - 1;
2963 txn->mt_flags = flags;
2966 txn->mt_numdbs = env->me_numdbs;
2967 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
2968 x = env->me_dbflags[i];
2969 txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
2970 txn->mt_dbflags[i] = (x & MDB_VALID) ? DB_VALID|DB_USRVALID|DB_STALE : 0;
2972 txn->mt_dbflags[MAIN_DBI] = DB_VALID|DB_USRVALID;
2973 txn->mt_dbflags[FREE_DBI] = DB_VALID;
2975 if (env->me_flags & MDB_FATAL_ERROR) {
2976 DPUTS("environment had fatal error, must shutdown!");
2978 } else if (env->me_maxpg < txn->mt_next_pgno) {
2979 rc = MDB_MAP_RESIZED;
2983 mdb_txn_end(txn, new_notls /*0 or MDB_END_SLOT*/ | MDB_END_FAIL_BEGIN);
2988 mdb_txn_renew(MDB_txn *txn)
2992 if (!txn || !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY|MDB_TXN_FINISHED))
2995 rc = mdb_txn_renew0(txn);
2996 if (rc == MDB_SUCCESS) {
2997 DPRINTF(("renew txn %"Y"u%c %p on mdbenv %p, root page %"Y"u",
2998 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
2999 (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root));
3005 mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
3009 int rc, size, tsize;
3011 flags &= MDB_TXN_BEGIN_FLAGS;
3012 flags |= env->me_flags & MDB_WRITEMAP;
3014 if (env->me_flags & MDB_RDONLY & ~flags) /* write txn in RDONLY env */
3018 /* Nested transactions: Max 1 child, write txns only, no writemap */
3019 flags |= parent->mt_flags;
3020 if (flags & (MDB_RDONLY|MDB_WRITEMAP|MDB_TXN_BLOCKED)) {
3021 return (parent->mt_flags & MDB_TXN_RDONLY) ? EINVAL : MDB_BAD_TXN;
3023 /* Child txns save MDB_pgstate and use own copy of cursors */
3024 size = env->me_maxdbs * (sizeof(MDB_db)+sizeof(MDB_cursor *)+1);
3025 size += tsize = sizeof(MDB_ntxn);
3026 } else if (flags & MDB_RDONLY) {
3027 size = env->me_maxdbs * (sizeof(MDB_db)+1);
3028 size += tsize = sizeof(MDB_txn);
3030 /* Reuse preallocated write txn. However, do not touch it until
3031 * mdb_txn_renew0() succeeds, since it currently may be active.
3036 if ((txn = calloc(1, size)) == NULL) {
3037 DPRINTF(("calloc: %s", strerror(errno)));
3042 txn->mt_rpages = malloc(MDB_TRPAGE_SIZE * sizeof(MDB_ID3));
3043 if (!txn->mt_rpages) {
3047 txn->mt_rpages[0].mid = 0;
3048 txn->mt_rpcheck = MDB_TRPAGE_SIZE/2;
3051 txn->mt_dbxs = env->me_dbxs; /* static */
3052 txn->mt_dbs = (MDB_db *) ((char *)txn + tsize);
3053 txn->mt_dbflags = (unsigned char *)txn + size - env->me_maxdbs;
3054 txn->mt_flags = flags;
3059 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
3060 txn->mt_dbiseqs = parent->mt_dbiseqs;
3061 txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE);
3062 if (!txn->mt_u.dirty_list ||
3063 !(txn->mt_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)))
3065 free(txn->mt_u.dirty_list);
3069 txn->mt_txnid = parent->mt_txnid;
3070 txn->mt_dirty_room = parent->mt_dirty_room;
3071 txn->mt_u.dirty_list[0].mid = 0;
3072 txn->mt_spill_pgs = NULL;
3073 txn->mt_next_pgno = parent->mt_next_pgno;
3074 parent->mt_flags |= MDB_TXN_HAS_CHILD;
3075 parent->mt_child = txn;
3076 txn->mt_parent = parent;
3077 txn->mt_numdbs = parent->mt_numdbs;
3079 txn->mt_rpages = parent->mt_rpages;
3081 memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
3082 /* Copy parent's mt_dbflags, but clear DB_NEW */
3083 for (i=0; i<txn->mt_numdbs; i++)
3084 txn->mt_dbflags[i] = parent->mt_dbflags[i] & ~DB_NEW;
3086 ntxn = (MDB_ntxn *)txn;
3087 ntxn->mnt_pgstate = env->me_pgstate; /* save parent me_pghead & co */
3088 if (env->me_pghead) {
3089 size = MDB_IDL_SIZEOF(env->me_pghead);
3090 env->me_pghead = mdb_midl_alloc(env->me_pghead[0]);
3092 memcpy(env->me_pghead, ntxn->mnt_pgstate.mf_pghead, size);
3097 rc = mdb_cursor_shadow(parent, txn);
3099 mdb_txn_end(txn, MDB_END_FAIL_BEGINCHILD);
3100 } else { /* MDB_RDONLY */
3101 txn->mt_dbiseqs = env->me_dbiseqs;
3103 rc = mdb_txn_renew0(txn);
3106 if (txn != env->me_txn0) {
3108 free(txn->mt_rpages);
3113 txn->mt_flags |= flags; /* could not change txn=me_txn0 earlier */
3115 DPRINTF(("begin txn %"Y"u%c %p on mdbenv %p, root page %"Y"u",
3116 txn->mt_txnid, (flags & MDB_RDONLY) ? 'r' : 'w',
3117 (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root));
3124 mdb_txn_env(MDB_txn *txn)
3126 if(!txn) return NULL;
3131 mdb_txn_id(MDB_txn *txn)
3134 return txn->mt_txnid;
3137 /** Export or close DBI handles opened in this txn. */
3139 mdb_dbis_update(MDB_txn *txn, int keep)
3142 MDB_dbi n = txn->mt_numdbs;
3143 MDB_env *env = txn->mt_env;
3144 unsigned char *tdbflags = txn->mt_dbflags;
3146 for (i = n; --i >= CORE_DBS;) {
3147 if (tdbflags[i] & DB_NEW) {
3149 env->me_dbflags[i] = txn->mt_dbs[i].md_flags | MDB_VALID;
3151 char *ptr = env->me_dbxs[i].md_name.mv_data;
3153 env->me_dbxs[i].md_name.mv_data = NULL;
3154 env->me_dbxs[i].md_name.mv_size = 0;
3155 env->me_dbflags[i] = 0;
3156 env->me_dbiseqs[i]++;
3162 if (keep && env->me_numdbs < n)
3166 /** End a transaction, except successful commit of a nested transaction.
3167 * May be called twice for readonly txns: First reset it, then abort.
3168 * @param[in] txn the transaction handle to end
3169 * @param[in] mode why and how to end the transaction
3172 mdb_txn_end(MDB_txn *txn, unsigned mode)
3174 MDB_env *env = txn->mt_env;
3176 static const char *const names[] = MDB_END_NAMES;
3179 /* Export or close DBI handles opened in this txn */
3180 mdb_dbis_update(txn, mode & MDB_END_UPDATE);
3182 DPRINTF(("%s txn %"Y"u%c %p on mdbenv %p, root page %"Y"u",
3183 names[mode & MDB_END_OPMASK],
3184 txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w',
3185 (void *) txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root));
3187 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
3188 if (txn->mt_u.reader) {
3189 txn->mt_u.reader->mr_txnid = (txnid_t)-1;
3190 if (!(env->me_flags & MDB_NOTLS)) {
3191 txn->mt_u.reader = NULL; /* txn does not own reader */
3192 } else if (mode & MDB_END_SLOT) {
3193 txn->mt_u.reader->mr_pid = 0;
3194 txn->mt_u.reader = NULL;
3195 } /* else txn owns the slot until it does MDB_END_SLOT */
3197 txn->mt_numdbs = 0; /* prevent further DBI activity */
3198 txn->mt_flags |= MDB_TXN_FINISHED;
3200 } else if (!F_ISSET(txn->mt_flags, MDB_TXN_FINISHED)) {
3201 pgno_t *pghead = env->me_pghead;
3203 if (!(mode & MDB_END_UPDATE)) /* !(already closed cursors) */
3204 mdb_cursors_close(txn, 0);
3205 if (!(env->me_flags & MDB_WRITEMAP)) {
3206 mdb_dlist_free(txn);
3210 txn->mt_flags = MDB_TXN_FINISHED;
3212 if (!txn->mt_parent) {
3213 mdb_midl_shrink(&txn->mt_free_pgs);
3214 env->me_free_pgs = txn->mt_free_pgs;
3216 env->me_pghead = NULL;
3220 mode = 0; /* txn == env->me_txn0, do not free() it */
3222 /* The writer mutex was locked in mdb_txn_begin. */
3224 UNLOCK_MUTEX(env->me_wmutex);
3226 txn->mt_parent->mt_child = NULL;
3227 txn->mt_parent->mt_flags &= ~MDB_TXN_HAS_CHILD;
3228 env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
3229 mdb_midl_free(txn->mt_free_pgs);
3230 mdb_midl_free(txn->mt_spill_pgs);
3231 free(txn->mt_u.dirty_list);
3234 mdb_midl_free(pghead);
3237 if (!txn->mt_parent) {
3238 MDB_ID3L el = env->me_rpages, tl = txn->mt_rpages;
3239 unsigned i, x, n = tl[0].mid;
3240 pthread_mutex_lock(&env->me_rpmutex);
3241 for (i = 1; i <= n; i++) {
3242 if (tl[i].mid & (MDB_RPAGE_CHUNK-1)) {
3243 /* tmp overflow pages that we didn't share in env */
3244 munmap(tl[i].mptr, tl[i].mcnt * env->me_psize);
3246 x = mdb_mid3l_search(el, tl[i].mid);
3247 if (tl[i].mptr == el[x].mptr) {
3250 /* another tmp overflow page */
3251 munmap(tl[i].mptr, tl[i].mcnt * env->me_psize);
3255 pthread_mutex_unlock(&env->me_rpmutex);
3257 if (mode & MDB_END_FREE)
3261 if (mode & MDB_END_FREE)
3266 mdb_txn_reset(MDB_txn *txn)
3271 /* This call is only valid for read-only txns */
3272 if (!(txn->mt_flags & MDB_TXN_RDONLY))
3275 mdb_txn_end(txn, MDB_END_RESET);
3279 mdb_txn_abort(MDB_txn *txn)
3285 mdb_txn_abort(txn->mt_child);
3287 mdb_txn_end(txn, MDB_END_ABORT|MDB_END_SLOT|MDB_END_FREE);
3290 /** Save the freelist as of this transaction to the freeDB.
3291 * This changes the freelist. Keep trying until it stabilizes.
3293 * When (MDB_DEVEL) & 2, the changes do not affect #mdb_page_alloc(),
3294 * it then uses the transaction's original snapshot of the freeDB.
3297 mdb_freelist_save(MDB_txn *txn)
3299 /* env->me_pghead[] can grow and shrink during this call.
3300 * env->me_pglast and txn->mt_free_pgs[] can only grow.
3301 * Page numbers cannot disappear from txn->mt_free_pgs[].
3304 MDB_env *env = txn->mt_env;
3305 int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1;
3306 txnid_t pglast = 0, head_id = 0;
3307 pgno_t freecnt = 0, *free_pgs, *mop;
3308 ssize_t head_room = 0, total_room = 0, mop_len, clean_limit;
3310 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
3312 if (env->me_pghead) {
3313 /* Make sure first page of freeDB is touched and on freelist */
3314 rc = mdb_page_search(&mc, NULL, MDB_PS_FIRST|MDB_PS_MODIFY);
3315 if (rc && rc != MDB_NOTFOUND)
3319 if (!env->me_pghead && txn->mt_loose_pgs) {
3320 /* Put loose page numbers in mt_free_pgs, since
3321 * we may be unable to return them to me_pghead.
3323 MDB_page *mp = txn->mt_loose_pgs;
3324 if ((rc = mdb_midl_need(&txn->mt_free_pgs, txn->mt_loose_count)) != 0)
3326 for (; mp; mp = NEXT_LOOSE_PAGE(mp))
3327 mdb_midl_xappend(txn->mt_free_pgs, mp->mp_pgno);
3328 txn->mt_loose_pgs = NULL;
3329 txn->mt_loose_count = 0;
3332 /* MDB_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
3333 clean_limit = (env->me_flags & (MDB_NOMEMINIT|MDB_WRITEMAP))
3334 ? SSIZE_MAX : maxfree_1pg;
3337 /* Come back here after each Put() in case freelist changed */
3342 /* If using records from freeDB which we have not yet
3343 * deleted, delete them and any we reserved for me_pghead.
3345 while (pglast < env->me_pglast) {
3346 rc = mdb_cursor_first(&mc, &key, NULL);
3349 pglast = head_id = *(txnid_t *)key.mv_data;
3350 total_room = head_room = 0;
3351 mdb_tassert(txn, pglast <= env->me_pglast);
3352 rc = mdb_cursor_del(&mc, 0);
3357 /* Save the IDL of pages freed by this txn, to a single record */
3358 if (freecnt < txn->mt_free_pgs[0]) {
3360 /* Make sure last page of freeDB is touched and on freelist */
3361 rc = mdb_page_search(&mc, NULL, MDB_PS_LAST|MDB_PS_MODIFY);
3362 if (rc && rc != MDB_NOTFOUND)
3365 free_pgs = txn->mt_free_pgs;
3366 /* Write to last page of freeDB */
3367 key.mv_size = sizeof(txn->mt_txnid);
3368 key.mv_data = &txn->mt_txnid;
3370 freecnt = free_pgs[0];
3371 data.mv_size = MDB_IDL_SIZEOF(free_pgs);
3372 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
3375 /* Retry if mt_free_pgs[] grew during the Put() */
3376 free_pgs = txn->mt_free_pgs;
3377 } while (freecnt < free_pgs[0]);
3378 mdb_midl_sort(free_pgs);
3379 memcpy(data.mv_data, free_pgs, data.mv_size);
3382 unsigned int i = free_pgs[0];
3383 DPRINTF(("IDL write txn %"Y"u root %"Y"u num %u",
3384 txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, i));
3386 DPRINTF(("IDL %"Y"u", free_pgs[i]));
3392 mop = env->me_pghead;
3393 mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count;
3395 /* Reserve records for me_pghead[]. Split it if multi-page,
3396 * to avoid searching freeDB for a page range. Use keys in
3397 * range [1,me_pglast]: Smaller than txnid of oldest reader.
3399 if (total_room >= mop_len) {
3400 if (total_room == mop_len || --more < 0)
3402 } else if (head_room >= maxfree_1pg && head_id > 1) {
3403 /* Keep current record (overflow page), add a new one */
3407 /* (Re)write {key = head_id, IDL length = head_room} */
3408 total_room -= head_room;
3409 head_room = mop_len - total_room;
3410 if (head_room > maxfree_1pg && head_id > 1) {
3411 /* Overflow multi-page for part of me_pghead */
3412 head_room /= head_id; /* amortize page sizes */
3413 head_room += maxfree_1pg - head_room % (maxfree_1pg + 1);
3414 } else if (head_room < 0) {
3415 /* Rare case, not bothering to delete this record */
3418 key.mv_size = sizeof(head_id);
3419 key.mv_data = &head_id;
3420 data.mv_size = (head_room + 1) * sizeof(pgno_t);
3421 rc = mdb_cursor_put(&mc, &key, &data, MDB_RESERVE);
3424 /* IDL is initially empty, zero out at least the length */
3425 pgs = (pgno_t *)data.mv_data;
3426 j = head_room > clean_limit ? head_room : 0;
3430 total_room += head_room;
3433 /* Return loose page numbers to me_pghead, though usually none are
3434 * left at this point. The pages themselves remain in dirty_list.
3436 if (txn->mt_loose_pgs) {
3437 MDB_page *mp = txn->mt_loose_pgs;
3438 unsigned count = txn->mt_loose_count;
3440 /* Room for loose pages + temp IDL with same */
3441 if ((rc = mdb_midl_need(&env->me_pghead, 2*count+1)) != 0)
3443 mop = env->me_pghead;
3444 loose = mop + MDB_IDL_ALLOCLEN(mop) - count;
3445 for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp))
3446 loose[ ++count ] = mp->mp_pgno;
3448 mdb_midl_sort(loose);
3449 mdb_midl_xmerge(mop, loose);
3450 txn->mt_loose_pgs = NULL;
3451 txn->mt_loose_count = 0;
3455 /* Fill in the reserved me_pghead records */
3461 rc = mdb_cursor_first(&mc, &key, &data);
3462 for (; !rc; rc = mdb_cursor_next(&mc, &key, &data, MDB_NEXT)) {
3463 txnid_t id = *(txnid_t *)key.mv_data;
3464 ssize_t len = (ssize_t)(data.mv_size / sizeof(MDB_ID)) - 1;
3467 mdb_tassert(txn, len >= 0 && id <= env->me_pglast);
3469 if (len > mop_len) {
3471 data.mv_size = (len + 1) * sizeof(MDB_ID);
3473 data.mv_data = mop -= len;
3476 rc = mdb_cursor_put(&mc, &key, &data, MDB_CURRENT);
3478 if (rc || !(mop_len -= len))
3485 /** Flush (some) dirty pages to the map, after clearing their dirty flag.
3486 * @param[in] txn the transaction that's being committed
3487 * @param[in] keep number of initial pages in dirty_list to keep dirty.
3488 * @return 0 on success, non-zero on failure.
3491 mdb_page_flush(MDB_txn *txn, int keep)
3493 MDB_env *env = txn->mt_env;
3494 MDB_ID2L dl = txn->mt_u.dirty_list;
3495 unsigned psize = env->me_psize, j;
3496 int i, pagecount = dl[0].mid, rc;
3500 MDB_page *dp = NULL;
3504 struct iovec iov[MDB_COMMIT_PAGES];
3505 ssize_t wsize = 0, wres;
3506 off_t wpos = 0, next_pos = 1; /* impossible pos, so pos != next_pos */
3512 if (env->me_flags & MDB_WRITEMAP) {
3513 /* Clear dirty flags */
3514 while (++i <= pagecount) {
3516 /* Don't flush this page yet */
3517 if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
3518 dp->mp_flags &= ~P_KEEP;
3522 dp->mp_flags &= ~P_DIRTY;
3527 /* Write the pages */
3529 if (++i <= pagecount) {
3531 /* Don't flush this page yet */
3532 if (dp->mp_flags & (P_LOOSE|P_KEEP)) {
3533 dp->mp_flags &= ~P_KEEP;
3538 /* clear dirty flag */
3539 dp->mp_flags &= ~P_DIRTY;
3542 if (IS_OVERFLOW(dp)) size *= dp->mp_pages;
3547 /* Windows actually supports scatter/gather I/O, but only on
3548 * unbuffered file handles. Since we're relying on the OS page
3549 * cache for all our data, that's self-defeating. So we just
3550 * write pages one at a time. We use the ov structure to set
3551 * the write offset, to at least save the overhead of a Seek
3554 DPRINTF(("committing page %"Y"u", pgno));
3555 memset(&ov, 0, sizeof(ov));
3556 ov.Offset = pos & 0xffffffff;
3557 ov.OffsetHigh = pos >> 16 >> 16;
3558 if (!WriteFile(env->me_fd, dp, size, NULL, &ov)) {
3560 DPRINTF(("WriteFile: %d", rc));
3564 /* Write up to MDB_COMMIT_PAGES dirty pages at a time. */
3565 if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {
3568 /* Write previous page(s) */
3569 #ifdef MDB_USE_PWRITEV
3570 wres = pwritev(env->me_fd, iov, n, wpos);
3573 wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
3576 if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
3580 DPRINTF(("lseek: %s", strerror(rc)));
3583 wres = writev(env->me_fd, iov, n);
3586 if (wres != wsize) {
3591 DPRINTF(("Write error: %s", strerror(rc)));
3593 rc = EIO; /* TODO: Use which error code? */
3594 DPUTS("short write, filesystem full?");
3605 DPRINTF(("committing page %"Y"u", pgno));
3606 next_pos = pos + size;
3607 iov[n].iov_len = size;
3608 iov[n].iov_base = (char *)dp;
3614 if (pgno > txn->mt_last_pgno)
3615 txn->mt_last_pgno = pgno;
3618 /* MIPS has cache coherency issues, this is a no-op everywhere else
3619 * Note: for any size >= on-chip cache size, entire on-chip cache is
3622 CACHEFLUSH(env->me_map, txn->mt_next_pgno * env->me_psize, DCACHE);
3624 for (i = keep; ++i <= pagecount; ) {
3626 /* This is a page we skipped above */
3629 dl[j].mid = dp->mp_pgno;
3632 mdb_dpage_free(env, dp);
3637 txn->mt_dirty_room += i - j;
3643 mdb_txn_commit(MDB_txn *txn)
3646 unsigned int i, end_mode;
3652 /* mdb_txn_end() mode for a commit which writes nothing */
3653 end_mode = MDB_END_EMPTY_COMMIT|MDB_END_UPDATE|MDB_END_SLOT|MDB_END_FREE;
3655 if (txn->mt_child) {
3656 rc = mdb_txn_commit(txn->mt_child);
3663 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
3667 if (txn->mt_flags & (MDB_TXN_FINISHED|MDB_TXN_ERROR)) {
3668 DPUTS("txn has failed/finished, can't commit");
3670 txn->mt_parent->mt_flags |= MDB_TXN_ERROR;
3675 if (txn->mt_parent) {
3676 MDB_txn *parent = txn->mt_parent;
3680 unsigned x, y, len, ps_len;
3682 /* Append our free list to parent's */
3683 rc = mdb_midl_append_list(&parent->mt_free_pgs, txn->mt_free_pgs);
3686 mdb_midl_free(txn->mt_free_pgs);
3687 /* Failures after this must either undo the changes
3688 * to the parent or set MDB_TXN_ERROR in the parent.
3691 parent->mt_next_pgno = txn->mt_next_pgno;
3692 parent->mt_flags = txn->mt_flags;
3694 /* Merge our cursors into parent's and close them */
3695 mdb_cursors_close(txn, 1);
3697 /* Update parent's DB table. */
3698 memcpy(parent->mt_dbs, txn->mt_dbs, txn->mt_numdbs * sizeof(MDB_db));
3699 parent->mt_numdbs = txn->mt_numdbs;
3700 parent->mt_dbflags[FREE_DBI] = txn->mt_dbflags[FREE_DBI];
3701 parent->mt_dbflags[MAIN_DBI] = txn->mt_dbflags[MAIN_DBI];
3702 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
3703 /* preserve parent's DB_NEW status */
3704 x = parent->mt_dbflags[i] & DB_NEW;
3705 parent->mt_dbflags[i] = txn->mt_dbflags[i] | x;
3708 dst = parent->mt_u.dirty_list;
3709 src = txn->mt_u.dirty_list;
3710 /* Remove anything in our dirty list from parent's spill list */
3711 if ((pspill = parent->mt_spill_pgs) && (ps_len = pspill[0])) {
3713 pspill[0] = (pgno_t)-1;
3714 /* Mark our dirty pages as deleted in parent spill list */
3715 for (i=0, len=src[0].mid; ++i <= len; ) {
3716 MDB_ID pn = src[i].mid << 1;
3717 while (pn > pspill[x])
3719 if (pn == pspill[x]) {
3724 /* Squash deleted pagenums if we deleted any */
3725 for (x=y; ++x <= ps_len; )
3726 if (!(pspill[x] & 1))
3727 pspill[++y] = pspill[x];
3731 /* Remove anything in our spill list from parent's dirty list */
3732 if (txn->mt_spill_pgs && txn->mt_spill_pgs[0]) {
3733 for (i=1; i<=txn->mt_spill_pgs[0]; i++) {
3734 MDB_ID pn = txn->mt_spill_pgs[i];
3736 continue; /* deleted spillpg */
3738 y = mdb_mid2l_search(dst, pn);
3739 if (y <= dst[0].mid && dst[y].mid == pn) {
3741 while (y < dst[0].mid) {
3750 /* Find len = length of merging our dirty list with parent's */
3752 dst[0].mid = 0; /* simplify loops */
3753 if (parent->mt_parent) {
3754 len = x + src[0].mid;
3755 y = mdb_mid2l_search(src, dst[x].mid + 1) - 1;
3756 for (i = x; y && i; y--) {
3757 pgno_t yp = src[y].mid;
3758 while (yp < dst[i].mid)
3760 if (yp == dst[i].mid) {
3765 } else { /* Simplify the above for single-ancestor case */
3766 len = MDB_IDL_UM_MAX - txn->mt_dirty_room;
3768 /* Merge our dirty list with parent's */
3770 for (i = len; y; dst[i--] = src[y--]) {
3771 pgno_t yp = src[y].mid;
3772 while (yp < dst[x].mid)
3773 dst[i--] = dst[x--];
3774 if (yp == dst[x].mid)
3775 free(dst[x--].mptr);
3777 mdb_tassert(txn, i == x);
3779 free(txn->mt_u.dirty_list);
3780 parent->mt_dirty_room = txn->mt_dirty_room;
3781 if (txn->mt_spill_pgs) {
3782 if (parent->mt_spill_pgs) {
3783 /* TODO: Prevent failure here, so parent does not fail */
3784 rc = mdb_midl_append_list(&parent->mt_spill_pgs, txn->mt_spill_pgs);
3786 parent->mt_flags |= MDB_TXN_ERROR;
3787 mdb_midl_free(txn->mt_spill_pgs);
3788 mdb_midl_sort(parent->mt_spill_pgs);
3790 parent->mt_spill_pgs = txn->mt_spill_pgs;
3794 /* Append our loose page list to parent's */
3795 for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(*lp))
3797 *lp = txn->mt_loose_pgs;
3798 parent->mt_loose_count += txn->mt_loose_count;
3800 parent->mt_child = NULL;
3801 mdb_midl_free(((MDB_ntxn *)txn)->mnt_pgstate.mf_pghead);
3806 if (txn != env->me_txn) {
3807 DPUTS("attempt to commit unknown transaction");
3812 mdb_cursors_close(txn, 0);
3814 if (!txn->mt_u.dirty_list[0].mid &&
3815 !(txn->mt_flags & (MDB_TXN_DIRTY|MDB_TXN_SPILLS)))
3818 DPRINTF(("committing txn %"Y"u %p on mdbenv %p, root page %"Y"u",
3819 txn->mt_txnid, (void*)txn, (void*)env, txn->mt_dbs[MAIN_DBI].md_root));
3821 /* Update DB root pointers */
3822 if (txn->mt_numdbs > CORE_DBS) {
3826 data.mv_size = sizeof(MDB_db);
3828 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
3829 for (i = CORE_DBS; i < txn->mt_numdbs; i++) {
3830 if (txn->mt_dbflags[i] & DB_DIRTY) {
3831 if (TXN_DBI_CHANGED(txn, i)) {
3835 data.mv_data = &txn->mt_dbs[i];
3836 rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data,
3844 rc = mdb_freelist_save(txn);
3848 mdb_midl_free(env->me_pghead);
3849 env->me_pghead = NULL;
3850 mdb_midl_shrink(&txn->mt_free_pgs);
3856 if ((rc = mdb_page_flush(txn, 0)))
3858 if (!F_ISSET(txn->mt_flags, MDB_TXN_NOSYNC) &&
3859 (rc = mdb_env_sync0(env, 0, txn->mt_next_pgno)))
3861 if ((rc = mdb_env_write_meta(txn)))
3863 end_mode = MDB_END_COMMITTED|MDB_END_UPDATE;
3866 mdb_txn_end(txn, end_mode);
3874 /** Read the environment parameters of a DB environment before
3875 * mapping it into memory.
3876 * @param[in] env the environment handle
3877 * @param[out] meta address of where to store the meta information
3878 * @return 0 on success, non-zero on failure.
3881 mdb_env_read_header(MDB_env *env, MDB_meta *meta)
3887 enum { Size = sizeof(pbuf) };
3889 /* We don't know the page size yet, so use a minimum value.
3890 * Read both meta pages so we can use the latest one.
3893 for (i=off=0; i<NUM_METAS; i++, off += meta->mm_psize) {
3897 memset(&ov, 0, sizeof(ov));
3899 rc = ReadFile(env->me_fd, &pbuf, Size, &len, &ov) ? (int)len : -1;
3900 if (rc == -1 && ErrCode() == ERROR_HANDLE_EOF)
3903 rc = pread(env->me_fd, &pbuf, Size, off);
3906 if (rc == 0 && off == 0)
3908 rc = rc < 0 ? (int) ErrCode() : MDB_INVALID;
3909 DPRINTF(("read: %s", mdb_strerror(rc)));
3913 p = (MDB_page *)&pbuf;
3915 if (!F_ISSET(p->mp_flags, P_META)) {
3916 DPRINTF(("page %"Y"u not a meta page", p->mp_pgno));
3921 if (m->mm_magic != MDB_MAGIC) {
3922 DPUTS("meta has invalid magic");
3926 if (m->mm_version != MDB_DATA_VERSION) {
3927 DPRINTF(("database is version %u, expected version %u",
3928 m->mm_version, MDB_DATA_VERSION));
3929 return MDB_VERSION_MISMATCH;
3932 if (off == 0 || m->mm_txnid > meta->mm_txnid)
3938 /** Fill in most of the zeroed #MDB_meta for an empty database environment */
3940 mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)
3942 meta->mm_magic = MDB_MAGIC;
3943 meta->mm_version = MDB_DATA_VERSION;
3944 meta->mm_mapsize = env->me_mapsize;
3945 meta->mm_psize = env->me_psize;
3946 meta->mm_last_pg = NUM_METAS-1;
3947 meta->mm_flags = env->me_flags & 0xffff;
3948 meta->mm_flags |= MDB_INTEGERKEY; /* this is mm_dbs[FREE_DBI].md_flags */
3949 meta->mm_dbs[FREE_DBI].md_root = P_INVALID;
3950 meta->mm_dbs[MAIN_DBI].md_root = P_INVALID;
3953 /** Write the environment parameters of a freshly created DB environment.
3954 * @param[in] env the environment handle
3955 * @param[in] meta the #MDB_meta to write
3956 * @return 0 on success, non-zero on failure.
3959 mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
3967 memset(&ov, 0, sizeof(ov));
3968 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3970 rc = WriteFile(fd, ptr, size, &len, &ov); } while(0)
3973 #define DO_PWRITE(rc, fd, ptr, size, len, pos) do { \
3974 len = pwrite(fd, ptr, size, pos); \
3975 if (len == -1 && ErrCode() == EINTR) continue; \
3976 rc = (len >= 0); break; } while(1)
3979 DPUTS("writing new meta page");
3981 psize = env->me_psize;
3983 p = calloc(NUM_METAS, psize);
3987 p->mp_flags = P_META;
3988 *(MDB_meta *)METADATA(p) = *meta;
3990 q = (MDB_page *)((char *)p + psize);
3992 q->mp_flags = P_META;
3993 *(MDB_meta *)METADATA(q) = *meta;
3995 DO_PWRITE(rc, env->me_fd, p, psize * NUM_METAS, len, 0);
3998 else if ((unsigned) len == psize * NUM_METAS)
4006 /** Update the environment info to commit a transaction.
4007 * @param[in] txn the transaction that's being committed
4008 * @return 0 on success, non-zero on failure.
4011 mdb_env_write_meta(MDB_txn *txn)
4014 MDB_meta meta, metab, *mp;
4018 int rc, len, toggle;
4027 toggle = txn->mt_txnid & 1;
4028 DPRINTF(("writing meta page %d for root page %"Y"u",
4029 toggle, txn->mt_dbs[MAIN_DBI].md_root));
4032 flags = txn->mt_flags | env->me_flags;
4033 mp = env->me_metas[toggle];
4034 mapsize = env->me_metas[toggle ^ 1]->mm_mapsize;
4035 /* Persist any increases of mapsize config */
4036 if (mapsize < env->me_mapsize)
4037 mapsize = env->me_mapsize;
4039 if (flags & MDB_WRITEMAP) {
4040 mp->mm_mapsize = mapsize;
4041 mp->mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
4042 mp->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
4043 mp->mm_last_pg = txn->mt_next_pgno - 1;
4044 #if (__GNUC__ * 100 + __GNUC_MINOR__ >= 404) && /* TODO: portability */ \
4045 !(defined(__i386__) || defined(__x86_64__))
4046 /* LY: issue a memory barrier, if not x86. ITS#7969 */
4047 __sync_synchronize();
4049 mp->mm_txnid = txn->mt_txnid;
4050 if (!(flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
4051 unsigned meta_size = env->me_psize;
4052 rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
4053 ptr = (char *)mp - PAGEHDRSZ;
4054 #ifndef _WIN32 /* POSIX msync() requires ptr = start of OS page */
4055 r2 = (ptr - env->me_map) & (env->me_os_psize - 1);
4059 if (MDB_MSYNC(ptr, meta_size, rc)) {
4066 metab.mm_txnid = mp->mm_txnid;
4067 metab.mm_last_pg = mp->mm_last_pg;
4069 meta.mm_mapsize = mapsize;
4070 meta.mm_dbs[FREE_DBI] = txn->mt_dbs[FREE_DBI];
4071 meta.mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
4072 meta.mm_last_pg = txn->mt_next_pgno - 1;
4073 meta.mm_txnid = txn->mt_txnid;
4075 off = offsetof(MDB_meta, mm_mapsize);
4076 ptr = (char *)&meta + off;
4077 len = sizeof(MDB_meta) - off;
4078 off += (char *)mp - env->me_map;
4080 /* Write to the SYNC fd */
4081 mfd = (flags & (MDB_NOSYNC|MDB_NOMETASYNC)) ? env->me_fd : env->me_mfd;
4084 memset(&ov, 0, sizeof(ov));
4086 if (!WriteFile(mfd, ptr, len, (DWORD *)&rc, &ov))
4091 rc = pwrite(mfd, ptr, len, off);
4094 rc = rc < 0 ? ErrCode() : EIO;
4099 DPUTS("write failed, disk error?");
4100 /* On a failure, the pagecache still contains the new data.
4101 * Write some old data back, to prevent it from being used.
4102 * Use the non-SYNC fd; we know it will fail anyway.
4104 meta.mm_last_pg = metab.mm_last_pg;
4105 meta.mm_txnid = metab.mm_txnid;
4107 memset(&ov, 0, sizeof(ov));
4109 WriteFile(env->me_fd, ptr, len, NULL, &ov);
4111 r2 = pwrite(env->me_fd, ptr, len, off);
4112 (void)r2; /* Silence warnings. We don't care about pwrite's return value */
4115 env->me_flags |= MDB_FATAL_ERROR;
4118 /* MIPS has cache coherency issues, this is a no-op everywhere else */
4119 CACHEFLUSH(env->me_map + off, len, DCACHE);
4121 /* Memory ordering issues are irrelevant; since the entire writer
4122 * is wrapped by wmutex, all of these changes will become visible
4123 * after the wmutex is unlocked. Since the DB is multi-version,
4124 * readers will get consistent data regardless of how fresh or
4125 * how stale their view of these values is.
4128 env->me_txns->mti_txnid = txn->mt_txnid;
4133 /** Check both meta pages to see which one is newer.
4134 * @param[in] env the environment handle
4135 * @return newest #MDB_meta.
4138 mdb_env_pick_meta(const MDB_env *env)
4140 MDB_meta *const *metas = env->me_metas;
4141 return metas[ metas[0]->mm_txnid < metas[1]->mm_txnid ];
4145 mdb_env_create(MDB_env **env)
4149 e = calloc(1, sizeof(MDB_env));
4153 e->me_maxreaders = DEFAULT_READERS;
4154 e->me_maxdbs = e->me_numdbs = CORE_DBS;
4155 e->me_fd = INVALID_HANDLE_VALUE;
4156 e->me_lfd = INVALID_HANDLE_VALUE;
4157 e->me_mfd = INVALID_HANDLE_VALUE;
4158 #ifdef MDB_USE_POSIX_SEM
4159 e->me_rmutex = SEM_FAILED;
4160 e->me_wmutex = SEM_FAILED;
4161 #elif defined MDB_USE_SYSV_SEM
4162 e->me_rmutex->semid = -1;
4163 e->me_wmutex->semid = -1;
4165 e->me_pid = getpid();
4166 GET_PAGESIZE(e->me_os_psize);
4167 VGMEMP_CREATE(e,0,0);
4173 /** @brief Map a result from an NTAPI call to WIN32. */
4175 mdb_nt2win32(NTSTATUS st)
4180 GetOverlappedResult(NULL, &o, &br, FALSE);
4181 return GetLastError();
4186 mdb_env_map(MDB_env *env, void *addr)
4189 unsigned int flags = env->me_flags;
4192 int access = SECTION_MAP_READ;
4196 ULONG pageprot = PAGE_READONLY, secprot, alloctype;
4198 if (flags & MDB_WRITEMAP) {
4199 access |= SECTION_MAP_WRITE;
4200 pageprot = PAGE_READWRITE;
4202 if (flags & MDB_RDONLY) {
4203 secprot = PAGE_READONLY;
4207 secprot = PAGE_READWRITE;
4208 msize = env->me_mapsize;
4209 alloctype = MEM_RESERVE;
4212 rc = NtCreateSection(&mh, access, NULL, NULL, secprot, SEC_RESERVE, env->me_fd);
4214 return mdb_nt2win32(rc);
4217 msize = NUM_METAS * env->me_psize;
4219 rc = NtMapViewOfSection(mh, GetCurrentProcess(), &map, 0, 0, NULL, &msize, ViewUnmap, alloctype, pageprot);
4226 return mdb_nt2win32(rc);
4231 env->me_map = mmap(addr, NUM_METAS * env->me_psize, PROT_READ, MAP_SHARED,
4233 if (env->me_map == MAP_FAILED) {
4238 int prot = PROT_READ;
4239 if (flags & MDB_WRITEMAP) {
4241 if (ftruncate(env->me_fd, env->me_mapsize) < 0)
4244 env->me_map = mmap(addr, env->me_mapsize, prot, MAP_SHARED,
4246 if (env->me_map == MAP_FAILED) {
4251 if (flags & MDB_NORDAHEAD) {
4252 /* Turn off readahead. It's harmful when the DB is larger than RAM. */
4254 madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
4256 #ifdef POSIX_MADV_RANDOM
4257 posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
4258 #endif /* POSIX_MADV_RANDOM */
4259 #endif /* MADV_RANDOM */
4263 /* Can happen because the address argument to mmap() is just a
4264 * hint. mmap() can pick another, e.g. if the range is in use.
4265 * The MAP_FIXED flag would prevent that, but then mmap could
4266 * instead unmap existing pages to make room for the new map.
4268 if (addr && env->me_map != addr)
4269 return EBUSY; /* TODO: Make a new MDB_* error code? */
4272 p = (MDB_page *)env->me_map;
4273 env->me_metas[0] = METADATA(p);
4274 env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + env->me_psize);
4280 mdb_env_set_mapsize(MDB_env *env, mdb_size_t size)
4282 /* If env is already open, caller is responsible for making
4283 * sure there are no active txns.
4293 meta = mdb_env_pick_meta(env);
4295 size = meta->mm_mapsize;
4297 /* Silently round up to minimum if the size is too small */
4298 mdb_size_t minsize = (meta->mm_last_pg + 1) * env->me_psize;
4303 /* For MDB_VL32 this bit is a noop since we dynamically remap
4304 * chunks of the DB anyway.
4306 munmap(env->me_map, env->me_mapsize);
4307 env->me_mapsize = size;
4308 old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
4309 rc = mdb_env_map(env, old);
4312 #endif /* !MDB_VL32 */
4314 env->me_mapsize = size;
4316 env->me_maxpg = env->me_mapsize / env->me_psize;
4321 mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs)
4325 env->me_maxdbs = dbs + CORE_DBS;
4330 mdb_env_set_maxreaders(MDB_env *env, unsigned int readers)
4332 if (env->me_map || readers < 1)
4334 env->me_maxreaders = readers;
4339 mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
4341 if (!env || !readers)
4343 *readers = env->me_maxreaders;
4348 mdb_fsize(HANDLE fd, mdb_size_t *size)
4351 LARGE_INTEGER fsize;
4353 if (!GetFileSizeEx(fd, &fsize))
4356 *size = fsize.QuadPart;
4368 #ifdef BROKEN_FDATASYNC
4369 #include <sys/utsname.h>
4370 #include <sys/vfs.h>
4373 /** Further setup required for opening an LMDB environment
4376 mdb_env_open2(MDB_env *env)
4378 unsigned int flags = env->me_flags;
4379 int i, newenv = 0, rc;
4383 /* See if we should use QueryLimited */
4385 if ((rc & 0xff) > 5)
4386 env->me_pidquery = MDB_PROCESS_QUERY_LIMITED_INFORMATION;
4388 env->me_pidquery = PROCESS_QUERY_INFORMATION;
4391 #ifdef BROKEN_FDATASYNC
4392 /* ext3/ext4 fdatasync is broken on some older Linux kernels.
4393 * https://lkml.org/lkml/2012/9/3/83
4394 * Kernels after 3.6-rc6 are known good.
4395 * https://lkml.org/lkml/2012/9/10/556
4396 * See if the DB is on ext3/ext4, then check for new enough kernel
4397 * Kernels 2.6.32.60, 2.6.34.15, 3.2.30, and 3.5.4 are also known
4402 fstatfs(env->me_fd, &st);
4403 while (st.f_type == 0xEF53) {
4407 if (uts.release[0] < '3') {
4408 if (!strncmp(uts.release, "2.6.32.", 7)) {
4409 i = atoi(uts.release+7);
4411 break; /* 2.6.32.60 and newer is OK */
4412 } else if (!strncmp(uts.release, "2.6.34.", 7)) {
4413 i = atoi(uts.release+7);
4415 break; /* 2.6.34.15 and newer is OK */
4417 } else if (uts.release[0] == '3') {
4418 i = atoi(uts.release+2);
4420 break; /* 3.6 and newer is OK */
4422 i = atoi(uts.release+4);
4424 break; /* 3.5.4 and newer is OK */
4425 } else if (i == 2) {
4426 i = atoi(uts.release+4);
4428 break; /* 3.2.30 and newer is OK */
4430 } else { /* 4.x and newer is OK */
4433 env->me_flags |= MDB_FSYNCONLY;
4439 if ((i = mdb_env_read_header(env, &meta)) != 0) {
4442 DPUTS("new mdbenv");
4444 env->me_psize = env->me_os_psize;
4445 if (env->me_psize > MAX_PAGESIZE)
4446 env->me_psize = MAX_PAGESIZE;
4447 memset(&meta, 0, sizeof(meta));
4448 mdb_env_init_meta0(env, &meta);
4449 meta.mm_mapsize = DEFAULT_MAPSIZE;
4451 env->me_psize = meta.mm_psize;
4454 /* Was a mapsize configured? */
4455 if (!env->me_mapsize) {
4456 env->me_mapsize = meta.mm_mapsize;
4459 /* Make sure mapsize >= committed data size. Even when using
4460 * mm_mapsize, which could be broken in old files (ITS#7789).
4462 mdb_size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
4463 if (env->me_mapsize < minsize)
4464 env->me_mapsize = minsize;
4466 meta.mm_mapsize = env->me_mapsize;
4468 if (newenv && !(flags & MDB_FIXEDMAP)) {
4469 /* mdb_env_map() may grow the datafile. Write the metapages
4470 * first, so the file will be valid if initialization fails.
4471 * Except with FIXEDMAP, since we do not yet know mm_address.
4472 * We could fill in mm_address later, but then a different
4473 * program might end up doing that - one with a memory layout
4474 * and map address which does not suit the main program.
4476 rc = mdb_env_init_meta(env, &meta);
4482 /* For FIXEDMAP, make sure the file is non-empty before we attempt to map it */
4486 rc = WriteFile(env->me_fd, &dummy, 1, &len, NULL);
4494 rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);
4499 if (flags & MDB_FIXEDMAP)
4500 meta.mm_address = env->me_map;
4501 i = mdb_env_init_meta(env, &meta);
4502 if (i != MDB_SUCCESS) {
4507 env->me_maxfree_1pg = (env->me_psize - PAGEHDRSZ) / sizeof(pgno_t) - 1;
4508 env->me_nodemax = (((env->me_psize - PAGEHDRSZ) / MDB_MINKEYS) & -2)
4510 #if !(MDB_MAXKEYSIZE)
4511 env->me_maxkey = env->me_nodemax - (NODESIZE + sizeof(MDB_db));
4513 env->me_maxpg = env->me_mapsize / env->me_psize;
4517 MDB_meta *meta = mdb_env_pick_meta(env);
4518 MDB_db *db = &meta->mm_dbs[MAIN_DBI];
4520 DPRINTF(("opened database version %u, pagesize %u",
4521 meta->mm_version, env->me_psize));
4522 DPRINTF(("using meta page %d", (int) (meta->mm_txnid & 1)));
4523 DPRINTF(("depth: %u", db->md_depth));
4524 DPRINTF(("entries: %"Y"u", db->md_entries));
4525 DPRINTF(("branch pages: %"Y"u", db->md_branch_pages));
4526 DPRINTF(("leaf pages: %"Y"u", db->md_leaf_pages));
4527 DPRINTF(("overflow pages: %"Y"u", db->md_overflow_pages));
4528 DPRINTF(("root: %"Y"u", db->md_root));
4536 /** Release a reader thread's slot in the reader lock table.
4537 * This function is called automatically when a thread exits.
4538 * @param[in] ptr This points to the slot in the reader lock table.
4541 mdb_env_reader_dest(void *ptr)
4543 MDB_reader *reader = ptr;
4549 /** Junk for arranging thread-specific callbacks on Windows. This is
4550 * necessarily platform and compiler-specific. Windows supports up
4551 * to 1088 keys. Let's assume nobody opens more than 64 environments
4552 * in a single process, for now. They can override this if needed.
4554 #ifndef MAX_TLS_KEYS
4555 #define MAX_TLS_KEYS 64
4557 static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS];
4558 static int mdb_tls_nkeys;
4560 static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr)
4564 case DLL_PROCESS_ATTACH: break;
4565 case DLL_THREAD_ATTACH: break;
4566 case DLL_THREAD_DETACH:
4567 for (i=0; i<mdb_tls_nkeys; i++) {
4568 MDB_reader *r = pthread_getspecific(mdb_tls_keys[i]);
4570 mdb_env_reader_dest(r);
4574 case DLL_PROCESS_DETACH: break;
4579 const PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
4581 PIMAGE_TLS_CALLBACK mdb_tls_cbp __attribute__((section (".CRT$XLB"))) = mdb_tls_callback;
4585 /* Force some symbol references.
4586 * _tls_used forces the linker to create the TLS directory if not already done
4587 * mdb_tls_cbp prevents whole-program-optimizer from dropping the symbol.
4589 #pragma comment(linker, "/INCLUDE:_tls_used")
4590 #pragma comment(linker, "/INCLUDE:mdb_tls_cbp")
4591 #pragma const_seg(".CRT$XLB")
4592 extern const PIMAGE_TLS_CALLBACK mdb_tls_cbp;
4593 const PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
4596 #pragma comment(linker, "/INCLUDE:__tls_used")
4597 #pragma comment(linker, "/INCLUDE:_mdb_tls_cbp")
4598 #pragma data_seg(".CRT$XLB")
4599 PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
4601 #endif /* WIN 32/64 */
4602 #endif /* !__GNUC__ */
4605 /** Downgrade the exclusive lock on the region back to shared */
4607 mdb_env_share_locks(MDB_env *env, int *excl)
4610 MDB_meta *meta = mdb_env_pick_meta(env);
4612 env->me_txns->mti_txnid = meta->mm_txnid;
4617 /* First acquire a shared lock. The Unlock will
4618 * then release the existing exclusive lock.
4620 memset(&ov, 0, sizeof(ov));
4621 if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
4624 UnlockFile(env->me_lfd, 0, 0, 1, 0);
4630 struct flock lock_info;
4631 /* The shared lock replaces the existing lock */
4632 memset((void *)&lock_info, 0, sizeof(lock_info));
4633 lock_info.l_type = F_RDLCK;
4634 lock_info.l_whence = SEEK_SET;
4635 lock_info.l_start = 0;
4636 lock_info.l_len = 1;
4637 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
4638 (rc = ErrCode()) == EINTR) ;
4639 *excl = rc ? -1 : 0; /* error may mean we lost the lock */
4646 /** Try to get exclusive lock, otherwise shared.
4647 * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive.
4650 mdb_env_excl_lock(MDB_env *env, int *excl)
4654 if (LockFile(env->me_lfd, 0, 0, 1, 0)) {
4658 memset(&ov, 0, sizeof(ov));
4659 if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
4666 struct flock lock_info;
4667 memset((void *)&lock_info, 0, sizeof(lock_info));
4668 lock_info.l_type = F_WRLCK;
4669 lock_info.l_whence = SEEK_SET;
4670 lock_info.l_start = 0;
4671 lock_info.l_len = 1;
4672 while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
4673 (rc = ErrCode()) == EINTR) ;
4677 # ifndef MDB_USE_POSIX_MUTEX
4678 if (*excl < 0) /* always true when MDB_USE_POSIX_MUTEX */
4681 lock_info.l_type = F_RDLCK;
4682 while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) &&
4683 (rc = ErrCode()) == EINTR) ;
4693 * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code
4695 * @(#) $Revision: 5.1 $
4696 * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $
4697 * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $
4699 * http://www.isthe.com/chongo/tech/comp/fnv/index.html
4703 * Please do not copyright this code. This code is in the public domain.
4705 * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
4706 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
4707 * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
4708 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
4709 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
4710 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
4711 * PERFORMANCE OF THIS SOFTWARE.
4714 * chongo <Landon Curt Noll> /\oo/\
4715 * http://www.isthe.com/chongo/
4717 * Share and Enjoy! :-)
4720 typedef unsigned long long mdb_hash_t;
4721 #define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
4723 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
4724 * @param[in] val value to hash
4725 * @param[in] hval initial value for hash
4726 * @return 64 bit hash
4728 * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
4729 * hval arg on the first call.
4732 mdb_hash_val(MDB_val *val, mdb_hash_t hval)
4734 unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */
4735 unsigned char *end = s + val->mv_size;
4737 * FNV-1a hash each octet of the string
4740 /* xor the bottom with the current octet */
4741 hval ^= (mdb_hash_t)*s++;
4743 /* multiply by the 64 bit FNV magic prime mod 2^64 */
4744 hval += (hval << 1) + (hval << 4) + (hval << 5) +
4745 (hval << 7) + (hval << 8) + (hval << 40);
4747 /* return our new hash value */
4751 /** Hash the string and output the encoded hash.
4752 * This uses modified RFC1924 Ascii85 encoding to accommodate systems with
4753 * very short name limits. We don't care about the encoding being reversible,
4754 * we just want to preserve as many bits of the input as possible in a
4755 * small printable string.
4756 * @param[in] str string to hash
4757 * @param[out] encbuf an array of 11 chars to hold the hash
4759 static const char mdb_a85[]= "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~";
4762 mdb_pack85(unsigned long l, char *out)
4766 for (i=0; i<5; i++) {
4767 *out++ = mdb_a85[l % 85];
4773 mdb_hash_enc(MDB_val *val, char *encbuf)
4775 mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT);
4777 mdb_pack85(h, encbuf);
4778 mdb_pack85(h>>32, encbuf+5);
4783 /** Open and/or initialize the lock region for the environment.
4784 * @param[in] env The LMDB environment.
4785 * @param[in] lpath The pathname of the file used for the lock region.
4786 * @param[in] mode The Unix permissions for the file, if we create it.
4787 * @param[in,out] excl In -1, out lock type: -1 none, 0 shared, 1 exclusive
4788 * @return 0 on success, non-zero on failure.
4791 mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
4794 # define MDB_ERRCODE_ROFS ERROR_WRITE_PROTECT
4796 # define MDB_ERRCODE_ROFS EROFS
4797 #ifdef O_CLOEXEC /* Linux: Open file and set FD_CLOEXEC atomically */
4798 # define MDB_CLOEXEC O_CLOEXEC
4801 # define MDB_CLOEXEC 0
4804 #ifdef MDB_USE_SYSV_SEM
4813 rc = utf8_to_utf16(lpath, -1, &wlpath, NULL);
4816 env->me_lfd = CreateFileW(wlpath, GENERIC_READ|GENERIC_WRITE,
4817 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
4818 FILE_ATTRIBUTE_NORMAL, NULL);
4821 env->me_lfd = open(lpath, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
4823 if (env->me_lfd == INVALID_HANDLE_VALUE) {
4825 if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
4830 #if ! ((MDB_CLOEXEC) || defined(_WIN32))
4831 /* Lose record locks when exec*() */
4832 if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
4833 fcntl(env->me_lfd, F_SETFD, fdflags);
4836 if (!(env->me_flags & MDB_NOTLS)) {
4837 rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
4840 env->me_flags |= MDB_ENV_TXKEY;
4842 /* Windows TLS callbacks need help finding their TLS info. */
4843 if (mdb_tls_nkeys >= MAX_TLS_KEYS) {
4847 mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey;
4851 /* Try to get exclusive lock. If we succeed, then
4852 * nobody is using the lock region and we should initialize it.
4854 if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
4857 size = GetFileSize(env->me_lfd, NULL);
4859 size = lseek(env->me_lfd, 0, SEEK_END);
4860 if (size == -1) goto fail_errno;
4862 rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
4863 if (size < rsize && *excl > 0) {
4865 if (SetFilePointer(env->me_lfd, rsize, NULL, FILE_BEGIN) != (DWORD)rsize
4866 || !SetEndOfFile(env->me_lfd))
4869 if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
4873 size = rsize - sizeof(MDB_txninfo);
4874 env->me_maxreaders = size/sizeof(MDB_reader) + 1;
4879 mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE,
4881 if (!mh) goto fail_errno;
4882 env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL);
4884 if (!env->me_txns) goto fail_errno;
4886 void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED,
4888 if (m == MAP_FAILED) goto fail_errno;
4894 BY_HANDLE_FILE_INFORMATION stbuf;
4903 if (!mdb_sec_inited) {
4904 InitializeSecurityDescriptor(&mdb_null_sd,
4905 SECURITY_DESCRIPTOR_REVISION);
4906 SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE);
4907 mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES);
4908 mdb_all_sa.bInheritHandle = FALSE;
4909 mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
4912 if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
4913 idbuf.volume = stbuf.dwVolumeSerialNumber;
4914 idbuf.nhigh = stbuf.nFileIndexHigh;
4915 idbuf.nlow = stbuf.nFileIndexLow;
4916 val.mv_data = &idbuf;
4917 val.mv_size = sizeof(idbuf);
4918 mdb_hash_enc(&val, encbuf);
4919 sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", encbuf);
4920 sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", encbuf);
4921 env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_rmname);
4922 if (!env->me_rmutex) goto fail_errno;
4923 env->me_wmutex = CreateMutexA(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
4924 if (!env->me_wmutex) goto fail_errno;
4925 #elif defined(MDB_USE_POSIX_SEM)
4934 #if defined(__NetBSD__)
4935 #define MDB_SHORT_SEMNAMES 1 /* limited to 14 chars */
4937 if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
4938 idbuf.dev = stbuf.st_dev;
4939 idbuf.ino = stbuf.st_ino;
4940 val.mv_data = &idbuf;
4941 val.mv_size = sizeof(idbuf);
4942 mdb_hash_enc(&val, encbuf);
4943 #ifdef MDB_SHORT_SEMNAMES
4944 encbuf[9] = '\0'; /* drop name from 15 chars to 14 chars */
4946 sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
4947 sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
4948 /* Clean up after a previous run, if needed: Try to
4949 * remove both semaphores before doing anything else.
4951 sem_unlink(env->me_txns->mti_rmname);
4952 sem_unlink(env->me_txns->mti_wmname);
4953 env->me_rmutex = sem_open(env->me_txns->mti_rmname,
4954 O_CREAT|O_EXCL, mode, 1);
4955 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
4956 env->me_wmutex = sem_open(env->me_txns->mti_wmname,
4957 O_CREAT|O_EXCL, mode, 1);
4958 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
4959 #elif defined(MDB_USE_SYSV_SEM)
4960 unsigned short vals[2] = {1, 1};
4961 key_t key = ftok(lpath, 'M');
4964 semid = semget(key, 2, (mode & 0777) | IPC_CREAT);
4968 if (semctl(semid, 0, SETALL, semu) < 0)
4970 env->me_txns->mti_semid = semid;
4971 env->me_txns->mti_rlocked = 0;
4972 env->me_txns->mti_wlocked = 0;
4973 #else /* MDB_USE_POSIX_MUTEX: */
4974 pthread_mutexattr_t mattr;
4976 /* Solaris needs this before initing a robust mutex. Otherwise
4977 * it may skip the init and return EBUSY "seems someone already
4978 * inited" or EINVAL "it was inited differently".
4980 memset(env->me_txns->mti_rmutex, 0, sizeof(*env->me_txns->mti_rmutex));
4981 memset(env->me_txns->mti_wmutex, 0, sizeof(*env->me_txns->mti_wmutex));
4983 if ((rc = pthread_mutexattr_init(&mattr)) != 0)
4985 rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED);
4986 #ifdef MDB_ROBUST_SUPPORTED
4987 if (!rc) rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST);
4989 if (!rc) rc = pthread_mutex_init(env->me_txns->mti_rmutex, &mattr);
4990 if (!rc) rc = pthread_mutex_init(env->me_txns->mti_wmutex, &mattr);
4991 pthread_mutexattr_destroy(&mattr);
4994 #endif /* _WIN32 || ... */
4996 env->me_txns->mti_magic = MDB_MAGIC;
4997 env->me_txns->mti_format = MDB_LOCK_FORMAT;
4998 env->me_txns->mti_txnid = 0;
4999 env->me_txns->mti_numreaders = 0;
5002 #ifdef MDB_USE_SYSV_SEM
5003 struct semid_ds buf;
5005 if (env->me_txns->mti_magic != MDB_MAGIC) {
5006 DPUTS("lock region has invalid magic");
5010 if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
5011 DPRINTF(("lock region has format+version 0x%x, expected 0x%x",
5012 env->me_txns->mti_format, MDB_LOCK_FORMAT));
5013 rc = MDB_VERSION_MISMATCH;
5017 if (rc && rc != EACCES && rc != EAGAIN) {
5021 env->me_rmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname);
5022 if (!env->me_rmutex) goto fail_errno;
5023 env->me_wmutex = OpenMutexA(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
5024 if (!env->me_wmutex) goto fail_errno;
5025 #elif defined(MDB_USE_POSIX_SEM)
5026 env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
5027 if (env->me_rmutex == SEM_FAILED) goto fail_errno;
5028 env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
5029 if (env->me_wmutex == SEM_FAILED) goto fail_errno;
5030 #elif defined(MDB_USE_SYSV_SEM)
5031 semid = env->me_txns->mti_semid;
5033 /* check for read access */
5034 if (semctl(semid, 0, IPC_STAT, semu) < 0)
5036 /* check for write access */
5037 if (semctl(semid, 0, IPC_SET, semu) < 0)
5041 #ifdef MDB_USE_SYSV_SEM
5042 env->me_rmutex->semid = semid;
5043 env->me_wmutex->semid = semid;
5044 env->me_rmutex->semnum = 0;
5045 env->me_wmutex->semnum = 1;
5046 env->me_rmutex->locked = &env->me_txns->mti_rlocked;
5047 env->me_wmutex->locked = &env->me_txns->mti_wlocked;
5051 env->me_rpmutex = CreateMutex(NULL, FALSE, NULL);
5053 pthread_mutex_init(&env->me_rpmutex, NULL);
5065 /** The name of the lock file in the DB environment */
5066 #define LOCKNAME "/lock.mdb"
5067 /** The name of the data file in the DB environment */
5068 #define DATANAME "/data.mdb"
5069 /** The suffix of the lock file when no subdir is used */
5070 #define LOCKSUFF "-lock"
5071 /** Only a subset of the @ref mdb_env flags can be changed
5072 * at runtime. Changing other flags requires closing the
5073 * environment and re-opening it with the new flags.
5075 #define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)
5076 #define CHANGELESS (MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY| \
5077 MDB_WRITEMAP|MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
5079 #if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)
5080 # error "Persistent DB flags & env flags overlap, but both go in mm_flags"
5084 mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
5086 int oflags, rc, len, excl = -1;
5087 char *lpath, *dpath;
5092 if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
5096 if (flags & MDB_WRITEMAP) {
5097 /* silently ignore WRITEMAP in 32 bit mode */
5098 flags ^= MDB_WRITEMAP;
5100 if (flags & MDB_FIXEDMAP) {
5101 /* cannot support FIXEDMAP */
5107 if (flags & MDB_NOSUBDIR) {
5108 rc = len + sizeof(LOCKSUFF) + len + 1;
5110 rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME);
5115 if (flags & MDB_NOSUBDIR) {
5116 dpath = lpath + len + sizeof(LOCKSUFF);
5117 sprintf(lpath, "%s" LOCKSUFF, path);
5118 strcpy(dpath, path);
5120 dpath = lpath + len + sizeof(LOCKNAME);
5121 sprintf(lpath, "%s" LOCKNAME, path);
5122 sprintf(dpath, "%s" DATANAME, path);
5126 flags |= env->me_flags;
5127 if (flags & MDB_RDONLY) {
5128 /* silently ignore WRITEMAP when we're only getting read access */
5129 flags &= ~MDB_WRITEMAP;
5131 if (!((env->me_free_pgs = mdb_midl_alloc(MDB_IDL_UM_MAX)) &&
5132 (env->me_dirty_list = calloc(MDB_IDL_UM_SIZE, sizeof(MDB_ID2)))))
5137 env->me_rpages = malloc(MDB_ERPAGE_SIZE * sizeof(MDB_ID3));
5138 if (!env->me_rpages) {
5142 env->me_rpages[0].mid = 0;
5143 env->me_rpcheck = MDB_ERPAGE_SIZE/2;
5146 env->me_flags = flags |= MDB_ENV_ACTIVE;
5150 env->me_path = strdup(path);
5151 env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx));
5152 env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t));
5153 env->me_dbiseqs = calloc(env->me_maxdbs, sizeof(unsigned int));
5154 if (!(env->me_dbxs && env->me_path && env->me_dbflags && env->me_dbiseqs)) {
5158 env->me_dbxs[FREE_DBI].md_cmp = mdb_cmp_long; /* aligned MDB_INTEGERKEY */
5160 /* For RDONLY, get lockfile after we know datafile exists */
5161 if (!(flags & (MDB_RDONLY|MDB_NOLOCK))) {
5162 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
5168 if (F_ISSET(flags, MDB_RDONLY)) {
5169 oflags = GENERIC_READ;
5170 len = OPEN_EXISTING;
5172 oflags = GENERIC_READ|GENERIC_WRITE;
5175 mode = FILE_ATTRIBUTE_NORMAL;
5176 rc = utf8_to_utf16(dpath, -1, &wpath, NULL);
5179 env->me_fd = CreateFileW(wpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
5180 NULL, len, mode, NULL);
5183 if (F_ISSET(flags, MDB_RDONLY))
5186 oflags = O_RDWR | O_CREAT;
5188 env->me_fd = open(dpath, oflags, mode);
5190 if (env->me_fd == INVALID_HANDLE_VALUE) {
5195 if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {
5196 rc = mdb_env_setup_locks(env, lpath, mode, &excl);
5201 if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
5202 if (flags & (MDB_RDONLY|MDB_WRITEMAP)) {
5203 env->me_mfd = env->me_fd;
5205 /* Synchronous fd for meta writes. Needed even with
5206 * MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
5209 len = OPEN_EXISTING;
5210 rc = utf8_to_utf16(dpath, -1, &wpath, NULL);
5213 env->me_mfd = CreateFileW(wpath, oflags,
5214 FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
5215 mode | FILE_FLAG_WRITE_THROUGH, NULL);
5219 env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode);
5221 if (env->me_mfd == INVALID_HANDLE_VALUE) {
5226 DPRINTF(("opened dbenv %p", (void *) env));
5228 rc = mdb_env_share_locks(env, &excl);
5232 if (!(flags & MDB_RDONLY)) {
5234 int tsize = sizeof(MDB_txn), size = tsize + env->me_maxdbs *
5235 (sizeof(MDB_db)+sizeof(MDB_cursor *)+sizeof(unsigned int)+1);
5236 if ((env->me_pbuf = calloc(1, env->me_psize)) &&
5237 (txn = calloc(1, size)))
5239 txn->mt_dbs = (MDB_db *)((char *)txn + tsize);
5240 txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
5241 txn->mt_dbiseqs = (unsigned int *)(txn->mt_cursors + env->me_maxdbs);
5242 txn->mt_dbflags = (unsigned char *)(txn->mt_dbiseqs + env->me_maxdbs);
5245 txn->mt_rpages = malloc(MDB_TRPAGE_SIZE * sizeof(MDB_ID3));
5246 if (!txn->mt_rpages) {
5251 txn->mt_rpages[0].mid = 0;
5252 txn->mt_rpcheck = MDB_TRPAGE_SIZE/2;
5254 txn->mt_dbxs = env->me_dbxs;
5255 txn->mt_flags = MDB_TXN_FINISHED;
5265 mdb_env_close0(env, excl);
5271 /** Destroy resources from mdb_env_open(), clear our readers & DBIs */
5273 mdb_env_close0(MDB_env *env, int excl)
5277 if (!(env->me_flags & MDB_ENV_ACTIVE))
5280 /* Doing this here since me_dbxs may not exist during mdb_env_close */
5282 for (i = env->me_maxdbs; --i >= CORE_DBS; )
5283 free(env->me_dbxs[i].md_name.mv_data);
5288 free(env->me_dbiseqs);
5289 free(env->me_dbflags);
5291 free(env->me_dirty_list);
5293 if (env->me_txn0 && env->me_txn0->mt_rpages)
5294 free(env->me_txn0->mt_rpages);
5296 for (x=1; x<=env->me_rpages[0].mid; x++)
5297 munmap(env->me_rpages[x].mptr, env->me_rpages[x].mcnt * env->me_psize);
5299 free(env->me_rpages);
5302 mdb_midl_free(env->me_free_pgs);
5304 if (env->me_flags & MDB_ENV_TXKEY) {
5305 pthread_key_delete(env->me_txkey);
5307 /* Delete our key from the global list */
5308 for (i=0; i<mdb_tls_nkeys; i++)
5309 if (mdb_tls_keys[i] == env->me_txkey) {
5310 mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1];
5319 munmap(env->me_map, NUM_METAS*env->me_psize);
5321 munmap(env->me_map, env->me_mapsize);
5324 if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE)
5325 (void) close(env->me_mfd);
5326 if (env->me_fd != INVALID_HANDLE_VALUE)
5327 (void) close(env->me_fd);
5329 MDB_PID_T pid = env->me_pid;
5330 /* Clearing readers is done in this function because
5331 * me_txkey with its destructor must be disabled first.
5333 * We skip the the reader mutex, so we touch only
5334 * data owned by this process (me_close_readers and
5335 * our readers), and clear each reader atomically.
5337 for (i = env->me_close_readers; --i >= 0; )
5338 if (env->me_txns->mti_readers[i].mr_pid == pid)
5339 env->me_txns->mti_readers[i].mr_pid = 0;
5341 if (env->me_rmutex) {
5342 CloseHandle(env->me_rmutex);
5343 if (env->me_wmutex) CloseHandle(env->me_wmutex);
5345 /* Windows automatically destroys the mutexes when
5346 * the last handle closes.
5348 #elif defined(MDB_USE_POSIX_SEM)
5349 if (env->me_rmutex != SEM_FAILED) {
5350 sem_close(env->me_rmutex);
5351 if (env->me_wmutex != SEM_FAILED)
5352 sem_close(env->me_wmutex);
5353 /* If we have the filelock: If we are the
5354 * only remaining user, clean up semaphores.
5357 mdb_env_excl_lock(env, &excl);
5359 sem_unlink(env->me_txns->mti_rmname);
5360 sem_unlink(env->me_txns->mti_wmname);
5363 #elif defined(MDB_USE_SYSV_SEM)
5364 if (env->me_rmutex->semid != -1) {
5365 /* If we have the filelock: If we are the
5366 * only remaining user, clean up semaphores.
5369 mdb_env_excl_lock(env, &excl);
5371 semctl(env->me_rmutex->semid, 0, IPC_RMID);
5374 munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
5376 if (env->me_lfd != INVALID_HANDLE_VALUE) {
5379 /* Unlock the lockfile. Windows would have unlocked it
5380 * after closing anyway, but not necessarily at once.
5382 UnlockFile(env->me_lfd, 0, 0, 1, 0);
5385 (void) close(env->me_lfd);
5389 if (env->me_fmh) CloseHandle(env->me_fmh);
5390 if (env->me_rpmutex) CloseHandle(env->me_rpmutex);
5392 pthread_mutex_destroy(&env->me_rpmutex);
5396 env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
5400 mdb_env_close(MDB_env *env)
5407 VGMEMP_DESTROY(env);
5408 while ((dp = env->me_dpages) != NULL) {
5409 VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next));
5410 env->me_dpages = dp->mp_next;
5414 mdb_env_close0(env, 0);
5418 /** Compare two items pointing at aligned mdb_size_t's */
5420 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
5422 return (*(mdb_size_t *)a->mv_data < *(mdb_size_t *)b->mv_data) ? -1 :
5423 *(mdb_size_t *)a->mv_data > *(mdb_size_t *)b->mv_data;
5426 /** Compare two items pointing at aligned unsigned int's.
5428 * This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp,
5429 * but #mdb_cmp_clong() is called instead if the data type is mdb_size_t.
5432 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
5434 return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 :
5435 *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data;
5438 /** Compare two items pointing at unsigned ints of unknown alignment.
5439 * Nodes and keys are guaranteed to be 2-byte aligned.
5442 mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
5444 #if BYTE_ORDER == LITTLE_ENDIAN
5445 unsigned short *u, *c;
5448 u = (unsigned short *) ((char *) a->mv_data + a->mv_size);
5449 c = (unsigned short *) ((char *) b->mv_data + a->mv_size);
5452 } while(!x && u > (unsigned short *)a->mv_data);
5455 unsigned short *u, *c, *end;
5458 end = (unsigned short *) ((char *) a->mv_data + a->mv_size);
5459 u = (unsigned short *)a->mv_data;
5460 c = (unsigned short *)b->mv_data;
5463 } while(!x && u < end);
5468 /** Compare two items lexically */
5470 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
5477 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
5483 diff = memcmp(a->mv_data, b->mv_data, len);
5484 return diff ? diff : len_diff<0 ? -1 : len_diff;
5487 /** Compare two items in reverse byte order */
5489 mdb_cmp_memnr(const MDB_val *a, const MDB_val *b)
5491 const unsigned char *p1, *p2, *p1_lim;
5495 p1_lim = (const unsigned char *)a->mv_data;
5496 p1 = (const unsigned char *)a->mv_data + a->mv_size;
5497 p2 = (const unsigned char *)b->mv_data + b->mv_size;
5499 len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size;
5505 while (p1 > p1_lim) {
5506 diff = *--p1 - *--p2;
5510 return len_diff<0 ? -1 : len_diff;
5513 /** Search for key within a page, using binary search.
5514 * Returns the smallest entry larger or equal to the key.
5515 * If exactp is non-null, stores whether the found entry was an exact match
5516 * in *exactp (1 or 0).
5517 * Updates the cursor index with the index of the found entry.
5518 * If no entry larger or equal to the key is found, returns NULL.
5521 mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp)
5523 unsigned int i = 0, nkeys;
5526 MDB_page *mp = mc->mc_pg[mc->mc_top];
5527 MDB_node *node = NULL;
5532 nkeys = NUMKEYS(mp);
5534 DPRINTF(("searching %u keys in %s %spage %"Y"u",
5535 nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "",
5538 low = IS_LEAF(mp) ? 0 : 1;
5540 cmp = mc->mc_dbx->md_cmp;
5542 /* Branch pages have no data, so if using integer keys,
5543 * alignment is guaranteed. Use faster mdb_cmp_int.
5545 if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) {
5546 if (NODEPTR(mp, 1)->mn_ksize == sizeof(mdb_size_t))
5553 nodekey.mv_size = mc->mc_db->md_pad;
5554 node = NODEPTR(mp, 0); /* fake */
5555 while (low <= high) {
5556 i = (low + high) >> 1;
5557 nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size);
5558 rc = cmp(key, &nodekey);
5559 DPRINTF(("found leaf index %u [%s], rc = %i",
5560 i, DKEY(&nodekey), rc));
5569 while (low <= high) {
5570 i = (low + high) >> 1;
5572 node = NODEPTR(mp, i);
5573 nodekey.mv_size = NODEKSZ(node);
5574 nodekey.mv_data = NODEKEY(node);
5576 rc = cmp(key, &nodekey);
5579 DPRINTF(("found leaf index %u [%s], rc = %i",
5580 i, DKEY(&nodekey), rc));
5582 DPRINTF(("found branch index %u [%s -> %"Y"u], rc = %i",
5583 i, DKEY(&nodekey), NODEPGNO(node), rc));
5594 if (rc > 0) { /* Found entry is less than the key. */
5595 i++; /* Skip to get the smallest entry larger than key. */
5597 node = NODEPTR(mp, i);
5600 *exactp = (rc == 0 && nkeys > 0);
5601 /* store the key index */
5602 mc->mc_ki[mc->mc_top] = i;
5604 /* There is no entry larger or equal to the key. */
5607 /* nodeptr is fake for LEAF2 */
5613 mdb_cursor_adjust(MDB_cursor *mc, func)
5617 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
5618 if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) {
5625 /** Pop a page off the top of the cursor's stack. */
5627 mdb_cursor_pop(MDB_cursor *mc)
5630 DPRINTF(("popping page %"Y"u off db %d cursor %p",
5631 mc->mc_pg[mc->mc_top]->mp_pgno, DDBI(mc), (void *) mc));
5637 mc->mc_flags &= ~C_INITIALIZED;
5642 /** Push a page onto the top of the cursor's stack. */
5644 mdb_cursor_push(MDB_cursor *mc, MDB_page *mp)
5646 DPRINTF(("pushing page %"Y"u on db %d cursor %p", mp->mp_pgno,
5647 DDBI(mc), (void *) mc));
5649 if (mc->mc_snum >= CURSOR_STACK) {
5650 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
5651 return MDB_CURSOR_FULL;
5654 mc->mc_top = mc->mc_snum++;
5655 mc->mc_pg[mc->mc_top] = mp;
5656 mc->mc_ki[mc->mc_top] = 0;
5662 /** Map a read-only page.
5663 * There are two levels of tracking in use, a per-txn list and a per-env list.
5664 * ref'ing and unref'ing the per-txn list is faster since it requires no
5665 * locking. Pages are cached in the per-env list for global reuse, and a lock
5666 * is required. Pages are not immediately unmapped when their refcnt goes to
5667 * zero; they hang around in case they will be reused again soon.
5669 * When the per-txn list gets full, all pages with refcnt=0 are purged from the
5670 * list and their refcnts in the per-env list are decremented.
5672 * When the per-env list gets full, all pages with refcnt=0 are purged from the
5673 * list and their pages are unmapped.
5675 * @note "full" means the list has reached its respective rpcheck threshold.
5676 * This threshold slowly raises if no pages could be purged on a given check,
5677 * and returns to its original value when enough pages were purged.
5679 * If purging doesn't free any slots, filling the per-txn list will return
5680 * MDB_TXN_FULL, and filling the per-env list returns MDB_MAP_FULL.
5682 * Reference tracking in a txn is imperfect, pages can linger with non-zero
5683 * refcnt even without active references. It was deemed to be too invasive
5684 * to add unrefs in every required location. However, all pages are unref'd
5685 * at the end of the transaction. This guarantees that no stale references
5686 * linger in the per-env list.
5688 * Usually we map chunks of 16 pages at a time, but if an overflow page begins
5689 * at the tail of the chunk we extend the chunk to include the entire overflow
5690 * page. Unfortunately, pages can be turned into overflow pages after their
5691 * chunk was already mapped. In that case we must remap the chunk if the
5692 * overflow page is referenced. If the chunk's refcnt is 0 we can just remap
5693 * it, otherwise we temporarily map a new chunk just for the overflow page.
5695 * @note this chunk handling means we cannot guarantee that a data item
5696 * returned from the DB will stay alive for the duration of the transaction:
5697 * We unref pages as soon as a cursor moves away from the page
5698 * A subsequent op may cause a purge, which may unmap any unref'd chunks
5699 * The caller must copy the data if it must be used later in the same txn.
5701 * Also - our reference counting revolves around cursors, but overflow pages
5702 * aren't pointed to by a cursor's page stack. We have to remember them
5703 * explicitly, in the added mc_ovpg field. A single cursor can only hold a
5704 * reference to one overflow page at a time.
5706 * @param[in] txn the transaction for this access.
5707 * @param[in] pgno the page number for the page to retrieve.
5708 * @param[out] ret address of a pointer where the page's address will be stored.
5709 * @return 0 on success, non-zero on failure.
5712 mdb_rpage_get(MDB_txn *txn, pgno_t pg0, MDB_page **ret)
5714 MDB_env *env = txn->mt_env;
5716 MDB_ID3L tl = txn->mt_rpages;
5717 MDB_ID3L el = env->me_rpages;
5721 int rc, retries = 1;
5725 #define SET_OFF(off,val) off.QuadPart = val
5726 #define MAP(rc,env,addr,len,off) \
5728 rc = NtMapViewOfSection(env->me_fmh, GetCurrentProcess(), &addr, 0, \
5729 len, &off, &len, ViewUnmap, (env->me_flags & MDB_RDONLY) ? 0 : MEM_RESERVE, PAGE_READONLY); \
5730 if (rc) rc = mdb_nt2win32(rc)
5734 #define SET_OFF(off,val) off = val
5735 #define MAP(rc,env,addr,len,off) \
5736 addr = mmap(NULL, len, PROT_READ, MAP_SHARED, env->me_fd, off); \
5737 rc = (addr == MAP_FAILED) ? errno : 0
5740 /* remember the offset of the actual page number, so we can
5741 * return the correct pointer at the end.
5743 rem = pg0 & (MDB_RPAGE_CHUNK-1);
5747 x = mdb_mid3l_search(tl, pgno);
5748 if (x <= tl[0].mid && tl[x].mid == pgno) {
5749 if (x != tl[0].mid && tl[x+1].mid == pg0)
5751 /* check for overflow size */
5752 p = (MDB_page *)((char *)tl[x].mptr + rem * env->me_psize);
5753 if (IS_OVERFLOW(p) && p->mp_pages + rem > tl[x].mcnt) {
5754 id3.mcnt = p->mp_pages + rem;
5755 len = id3.mcnt * env->me_psize;
5756 SET_OFF(off, pgno * env->me_psize);
5757 MAP(rc, env, id3.mptr, len, off);
5760 /* check for local-only page */
5762 mdb_tassert(txn, tl[x].mid != pg0);
5763 /* hope there's room to insert this locally.
5764 * setting mid here tells later code to just insert
5765 * this id3 instead of searching for a match.
5770 /* ignore the mapping we got from env, use new one */
5771 tl[x].mptr = id3.mptr;
5772 tl[x].mcnt = id3.mcnt;
5773 /* if no active ref, see if we can replace in env */
5776 pthread_mutex_lock(&env->me_rpmutex);
5777 i = mdb_mid3l_search(el, tl[x].mid);
5778 if (el[i].mref == 1) {
5779 /* just us, replace it */
5780 munmap(el[i].mptr, el[i].mcnt * env->me_psize);
5781 el[i].mptr = tl[x].mptr;
5782 el[i].mcnt = tl[x].mcnt;
5784 /* there are others, remove ourself */
5787 pthread_mutex_unlock(&env->me_rpmutex);
5791 id3.mptr = tl[x].mptr;
5792 id3.mcnt = tl[x].mcnt;
5798 if (tl[0].mid >= MDB_TRPAGE_MAX - txn->mt_rpcheck) {
5800 /* purge unref'd pages from our list and unref in env */
5801 pthread_mutex_lock(&env->me_rpmutex);
5804 for (i=1; i<=tl[0].mid; i++) {
5807 /* tmp overflow pages don't go to env */
5808 if (tl[i].mid & (MDB_RPAGE_CHUNK-1)) {
5809 munmap(tl[i].mptr, tl[i].mcnt * env->me_psize);
5812 x = mdb_mid3l_search(el, tl[i].mid);
5816 pthread_mutex_unlock(&env->me_rpmutex);
5818 /* we didn't find any unref'd chunks.
5819 * if we're out of room, fail.
5821 if (tl[0].mid >= MDB_TRPAGE_MAX)
5822 return MDB_TXN_FULL;
5823 /* otherwise, raise threshold for next time around
5826 txn->mt_rpcheck /= 2;
5828 /* we found some unused; consolidate the list */
5829 for (i=y+1; i<= tl[0].mid; i++)
5833 /* decrease the check threshold toward its original value */
5834 if (!txn->mt_rpcheck)
5835 txn->mt_rpcheck = 1;
5836 while (txn->mt_rpcheck < tl[0].mid && txn->mt_rpcheck < MDB_TRPAGE_SIZE/2)
5837 txn->mt_rpcheck *= 2;
5840 if (tl[0].mid < MDB_TRPAGE_SIZE) {
5844 /* don't map past last written page in read-only envs */
5845 if ((env->me_flags & MDB_RDONLY) && pgno + MDB_RPAGE_CHUNK-1 > txn->mt_last_pgno)
5846 id3.mcnt = txn->mt_last_pgno + 1 - pgno;
5848 id3.mcnt = MDB_RPAGE_CHUNK;
5849 len = id3.mcnt * env->me_psize;
5852 /* search for page in env */
5853 pthread_mutex_lock(&env->me_rpmutex);
5854 x = mdb_mid3l_search(el, pgno);
5855 if (x <= el[0].mid && el[x].mid == pgno) {
5856 id3.mptr = el[x].mptr;
5857 id3.mcnt = el[x].mcnt;
5858 /* check for overflow size */
5859 p = (MDB_page *)((char *)id3.mptr + rem * env->me_psize);
5860 if (IS_OVERFLOW(p) && p->mp_pages + rem > id3.mcnt) {
5861 id3.mcnt = p->mp_pages + rem;
5862 len = id3.mcnt * env->me_psize;
5863 SET_OFF(off, pgno * env->me_psize);
5864 MAP(rc, env, id3.mptr, len, off);
5868 munmap(el[x].mptr, env->me_psize * el[x].mcnt);
5869 el[x].mptr = id3.mptr;
5870 el[x].mcnt = id3.mcnt;
5873 pthread_mutex_unlock(&env->me_rpmutex);
5878 pthread_mutex_unlock(&env->me_rpmutex);
5881 if (el[0].mid >= MDB_ERPAGE_MAX - env->me_rpcheck) {
5882 /* purge unref'd pages */
5884 for (i=1; i<=el[0].mid; i++) {
5887 munmap(el[i].mptr, env->me_psize * el[i].mcnt);
5892 /* see if we can unref some local pages */
5897 if (el[0].mid >= MDB_ERPAGE_MAX) {
5898 pthread_mutex_unlock(&env->me_rpmutex);
5899 return MDB_MAP_FULL;
5901 env->me_rpcheck /= 2;
5903 for (i=y+1; i<= el[0].mid; i++)
5907 if (!env->me_rpcheck)
5908 env->me_rpcheck = 1;
5909 while (env->me_rpcheck < el[0].mid && env->me_rpcheck < MDB_ERPAGE_SIZE/2)
5910 env->me_rpcheck *= 2;
5913 SET_OFF(off, pgno * env->me_psize);
5914 MAP(rc, env, id3.mptr, len, off);
5917 pthread_mutex_unlock(&env->me_rpmutex);
5920 /* check for overflow size */
5921 p = (MDB_page *)((char *)id3.mptr + rem * env->me_psize);
5922 if (IS_OVERFLOW(p) && p->mp_pages + rem > id3.mcnt) {
5923 id3.mcnt = p->mp_pages + rem;
5924 munmap(id3.mptr, len);
5925 len = id3.mcnt * env->me_psize;
5926 MAP(rc, env, id3.mptr, len, off);
5930 mdb_mid3l_insert(el, &id3);
5931 pthread_mutex_unlock(&env->me_rpmutex);
5933 mdb_mid3l_insert(tl, &id3);
5935 return MDB_TXN_FULL;
5938 p = (MDB_page *)((char *)id3.mptr + rem * env->me_psize);
5939 #if MDB_DEBUG /* we don't need this check any more */
5940 if (IS_OVERFLOW(p)) {
5941 mdb_tassert(txn, p->mp_pages + rem <= id3.mcnt);
5949 /** Find the address of the page corresponding to a given page number.
5950 * @param[in] mc the cursor accessing the page.
5951 * @param[in] pgno the page number for the page to retrieve.
5952 * @param[out] ret address of a pointer where the page's address will be stored.
5953 * @param[out] lvl dirty_list inheritance level of found page. 1=current txn, 0=mapped page.
5954 * @return 0 on success, non-zero on failure.
5957 mdb_page_get(MDB_cursor *mc, pgno_t pgno, MDB_page **ret, int *lvl)
5959 MDB_txn *txn = mc->mc_txn;
5961 MDB_env *env = txn->mt_env;
5966 if (! (mc->mc_flags & (C_ORIG_RDONLY|C_WRITEMAP))) {
5970 MDB_ID2L dl = tx2->mt_u.dirty_list;
5972 /* Spilled pages were dirtied in this txn and flushed
5973 * because the dirty list got full. Bring this page
5974 * back in from the map (but don't unspill it here,
5975 * leave that unless page_touch happens again).
5977 if (tx2->mt_spill_pgs) {
5978 MDB_ID pn = pgno << 1;
5979 x = mdb_midl_search(tx2->mt_spill_pgs, pn);
5980 if (x <= tx2->mt_spill_pgs[0] && tx2->mt_spill_pgs[x] == pn) {
5982 int rc = mdb_rpage_get(txn, pgno, &p);
5986 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
5992 unsigned x = mdb_mid2l_search(dl, pgno);
5993 if (x <= dl[0].mid && dl[x].mid == pgno) {
5999 } while ((tx2 = tx2->mt_parent) != NULL);
6002 if (pgno < txn->mt_next_pgno) {
6006 int rc = mdb_rpage_get(txn, pgno, &p);
6011 p = (MDB_page *)(env->me_map + env->me_psize * pgno);
6014 DPRINTF(("page %"Y"u not found", pgno));
6015 txn->mt_flags |= MDB_TXN_ERROR;
6016 return MDB_PAGE_NOTFOUND;
6026 /** Finish #mdb_page_search() / #mdb_page_search_lowest().
6027 * The cursor is at the root page, set up the rest of it.
6030 mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int flags)
6032 MDB_page *mp = mc->mc_pg[mc->mc_top];
6036 while (IS_BRANCH(mp)) {
6040 DPRINTF(("branch page %"Y"u has %u keys", mp->mp_pgno, NUMKEYS(mp)));
6041 /* Don't assert on branch pages in the FreeDB. We can get here
6042 * while in the process of rebalancing a FreeDB branch page; we must
6043 * let that proceed. ITS#8336
6045 mdb_cassert(mc, !mc->mc_dbi || NUMKEYS(mp) > 1);
6046 DPRINTF(("found index 0 to page %"Y"u", NODEPGNO(NODEPTR(mp, 0))));
6048 if (flags & (MDB_PS_FIRST|MDB_PS_LAST)) {
6050 if (flags & MDB_PS_LAST)
6051 i = NUMKEYS(mp) - 1;
6054 node = mdb_node_search(mc, key, &exact);
6056 i = NUMKEYS(mp) - 1;
6058 i = mc->mc_ki[mc->mc_top];
6060 mdb_cassert(mc, i > 0);
6064 DPRINTF(("following index %u for key [%s]", i, DKEY(key)));
6067 mdb_cassert(mc, i < NUMKEYS(mp));
6068 node = NODEPTR(mp, i);
6070 if ((rc = mdb_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)
6073 mc->mc_ki[mc->mc_top] = i;
6074 if ((rc = mdb_cursor_push(mc, mp)))
6077 if (flags & MDB_PS_MODIFY) {
6078 if ((rc = mdb_page_touch(mc)) != 0)
6080 mp = mc->mc_pg[mc->mc_top];
6085 DPRINTF(("internal error, index points to a %02X page!?",
6087 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
6088 return MDB_CORRUPTED;
6091 DPRINTF(("found leaf page %"Y"u for key [%s]", mp->mp_pgno,
6092 key ? DKEY(key) : "null"));
6093 mc->mc_flags |= C_INITIALIZED;
6094 mc->mc_flags &= ~C_EOF;
6099 /** Search for the lowest key under the current branch page.
6100 * This just bypasses a NUMKEYS check in the current page
6101 * before calling mdb_page_search_root(), because the callers
6102 * are all in situations where the current page is known to
6106 mdb_page_search_lowest(MDB_cursor *mc)
6108 MDB_page *mp = mc->mc_pg[mc->mc_top];
6109 MDB_node *node = NODEPTR(mp, 0);
6112 if ((rc = mdb_page_get(mc, NODEPGNO(node), &mp, NULL)) != 0)
6115 mc->mc_ki[mc->mc_top] = 0;
6116 if ((rc = mdb_cursor_push(mc, mp)))
6118 return mdb_page_search_root(mc, NULL, MDB_PS_FIRST);
6121 /** Search for the page a given key should be in.
6122 * Push it and its parent pages on the cursor stack.
6123 * @param[in,out] mc the cursor for this operation.
6124 * @param[in] key the key to search for, or NULL for first/last page.
6125 * @param[in] flags If MDB_PS_MODIFY is set, visited pages in the DB
6126 * are touched (updated with new page numbers).
6127 * If MDB_PS_FIRST or MDB_PS_LAST is set, find first or last leaf.
6128 * This is used by #mdb_cursor_first() and #mdb_cursor_last().
6129 * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups.
6130 * @return 0 on success, non-zero on failure.
6133 mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
6138 /* Make sure the txn is still viable, then find the root from
6139 * the txn's db table and set it as the root of the cursor's stack.
6141 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED) {
6142 DPUTS("transaction may not be used now");
6145 /* Make sure we're using an up-to-date root */
6146 if (*mc->mc_dbflag & DB_STALE) {
6148 if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
6150 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
6151 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, 0);
6158 MDB_node *leaf = mdb_node_search(&mc2,
6159 &mc->mc_dbx->md_name, &exact);
6161 return MDB_NOTFOUND;
6162 if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
6163 return MDB_INCOMPATIBLE; /* not a named DB */
6164 rc = mdb_node_read(&mc2, leaf, &data);
6167 memcpy(&flags, ((char *) data.mv_data + offsetof(MDB_db, md_flags)),
6169 /* The txn may not know this DBI, or another process may
6170 * have dropped and recreated the DB with other flags.
6172 if ((mc->mc_db->md_flags & PERSISTENT_FLAGS) != flags)
6173 return MDB_INCOMPATIBLE;
6174 memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db));
6176 *mc->mc_dbflag &= ~DB_STALE;
6178 root = mc->mc_db->md_root;
6180 if (root == P_INVALID) { /* Tree is empty. */
6181 DPUTS("tree is empty");
6182 return MDB_NOTFOUND;
6186 mdb_cassert(mc, root > 1);
6187 if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root) {
6190 MDB_PAGE_UNREF(mc->mc_txn, mc->mc_pg[0]);
6192 if ((rc = mdb_page_get(mc, root, &mc->mc_pg[0], NULL)) != 0)
6199 for (i=1; i<mc->mc_snum; i++)
6200 MDB_PAGE_UNREF(mc->mc_txn, mc->mc_pg[i]);
6206 DPRINTF(("db %d root page %"Y"u has flags 0x%X",
6207 DDBI(mc), root, mc->mc_pg[0]->mp_flags));
6209 if (flags & MDB_PS_MODIFY) {
6210 if ((rc = mdb_page_touch(mc)))
6214 if (flags & MDB_PS_ROOTONLY)
6217 return mdb_page_search_root(mc, key, flags);
6221 mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
6223 MDB_txn *txn = mc->mc_txn;
6224 pgno_t pg = mp->mp_pgno;
6225 unsigned x = 0, ovpages = mp->mp_pages;
6226 MDB_env *env = txn->mt_env;
6227 MDB_IDL sl = txn->mt_spill_pgs;
6228 MDB_ID pn = pg << 1;
6231 DPRINTF(("free ov page %"Y"u (%d)", pg, ovpages));
6232 /* If the page is dirty or on the spill list we just acquired it,
6233 * so we should give it back to our current free list, if any.
6234 * Otherwise put it onto the list of pages we freed in this txn.
6236 * Won't create me_pghead: me_pglast must be inited along with it.
6237 * Unsupported in nested txns: They would need to hide the page
6238 * range in ancestor txns' dirty and spilled lists.
6240 if (env->me_pghead &&
6242 ((mp->mp_flags & P_DIRTY) ||
6243 (sl && (x = mdb_midl_search(sl, pn)) <= sl[0] && sl[x] == pn)))
6247 MDB_ID2 *dl, ix, iy;
6248 rc = mdb_midl_need(&env->me_pghead, ovpages);
6251 if (!(mp->mp_flags & P_DIRTY)) {
6252 /* This page is no longer spilled */
6259 /* Remove from dirty list */
6260 dl = txn->mt_u.dirty_list;
6262 for (ix = dl[x]; ix.mptr != mp; ix = iy) {
6268 mdb_cassert(mc, x > 1);
6270 dl[j] = ix; /* Unsorted. OK when MDB_TXN_ERROR. */
6271 txn->mt_flags |= MDB_TXN_ERROR;
6275 txn->mt_dirty_room++;
6276 if (!(env->me_flags & MDB_WRITEMAP))
6277 mdb_dpage_free(env, mp);
6279 /* Insert in me_pghead */
6280 mop = env->me_pghead;
6281 j = mop[0] + ovpages;
6282 for (i = mop[0]; i && mop[i] < pg; i--)
6288 rc = mdb_midl_append_range(&txn->mt_free_pgs, pg, ovpages);
6292 mc->mc_db->md_overflow_pages -= ovpages;
6296 /** Return the data associated with a given node.
6297 * @param[in] mc The cursor for this operation.
6298 * @param[in] leaf The node being read.
6299 * @param[out] data Updated to point to the node's data.
6300 * @return 0 on success, non-zero on failure.
6303 mdb_node_read(MDB_cursor *mc, MDB_node *leaf, MDB_val *data)
6305 MDB_page *omp; /* overflow page */
6310 MDB_PAGE_UNREF(mc->mc_txn, MC_OVPG(mc));
6311 MC_SET_OVPG(mc, NULL);
6313 if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
6314 data->mv_size = NODEDSZ(leaf);
6315 data->mv_data = NODEDATA(leaf);
6319 /* Read overflow data.
6321 data->mv_size = NODEDSZ(leaf);
6322 memcpy(&pgno, NODEDATA(leaf), sizeof(pgno));
6323 if ((rc = mdb_page_get(mc, pgno, &omp, NULL)) != 0) {
6324 DPRINTF(("read overflow page %"Y"u failed", pgno));
6327 data->mv_data = METADATA(omp);
6328 MC_SET_OVPG(mc, omp);
6334 mdb_get(MDB_txn *txn, MDB_dbi dbi,
6335 MDB_val *key, MDB_val *data)
6342 DPRINTF(("===> get db %u key [%s]", dbi, DKEY(key)));
6344 if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
6347 if (txn->mt_flags & MDB_TXN_BLOCKED)
6350 mdb_cursor_init(&mc, txn, dbi, &mx);
6351 rc = mdb_cursor_set(&mc, key, data, MDB_SET, &exact);
6352 /* unref all the pages when MDB_VL32 - caller must copy the data
6353 * before doing anything else
6355 MDB_CURSOR_UNREF(&mc, 1);
6359 /** Find a sibling for a page.
6360 * Replaces the page at the top of the cursor's stack with the
6361 * specified sibling, if one exists.
6362 * @param[in] mc The cursor for this operation.
6363 * @param[in] move_right Non-zero if the right sibling is requested,
6364 * otherwise the left sibling.
6365 * @return 0 on success, non-zero on failure.
6368 mdb_cursor_sibling(MDB_cursor *mc, int move_right)
6377 if (mc->mc_snum < 2) {
6378 return MDB_NOTFOUND; /* root has no siblings */
6382 op = mc->mc_pg[mc->mc_top];
6385 DPRINTF(("parent page is page %"Y"u, index %u",
6386 mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]));
6388 if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top]))
6389 : (mc->mc_ki[mc->mc_top] == 0)) {
6390 DPRINTF(("no more keys left, moving to %s sibling",
6391 move_right ? "right" : "left"));
6392 if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
6393 /* undo cursor_pop before returning */
6400 mc->mc_ki[mc->mc_top]++;
6402 mc->mc_ki[mc->mc_top]--;
6403 DPRINTF(("just moving to %s index key %u",
6404 move_right ? "right" : "left", mc->mc_ki[mc->mc_top]));
6406 mdb_cassert(mc, IS_BRANCH(mc->mc_pg[mc->mc_top]));
6408 MDB_PAGE_UNREF(mc->mc_txn, op);
6410 indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6411 if ((rc = mdb_page_get(mc, NODEPGNO(indx), &mp, NULL)) != 0) {
6412 /* mc will be inconsistent if caller does mc_snum++ as above */
6413 mc->mc_flags &= ~(C_INITIALIZED|C_EOF);
6417 mdb_cursor_push(mc, mp);
6419 mc->mc_ki[mc->mc_top] = NUMKEYS(mp)-1;
6424 /** Move the cursor to the next data item. */
6426 mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
6432 if ((mc->mc_flags & C_EOF) ||
6433 ((mc->mc_flags & C_DEL) && op == MDB_NEXT_DUP)) {
6434 return MDB_NOTFOUND;
6436 if (!(mc->mc_flags & C_INITIALIZED))
6437 return mdb_cursor_first(mc, key, data);
6439 mp = mc->mc_pg[mc->mc_top];
6441 if (mc->mc_db->md_flags & MDB_DUPSORT) {
6442 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6443 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6444 if (op == MDB_NEXT || op == MDB_NEXT_DUP) {
6445 rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT);
6446 if (op != MDB_NEXT || rc != MDB_NOTFOUND) {
6447 if (rc == MDB_SUCCESS)
6448 MDB_GET_KEY(leaf, key);
6453 MDB_CURSOR_UNREF(&mc->mc_xcursor->mx_cursor, 0);
6456 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6457 if (op == MDB_NEXT_DUP)
6458 return MDB_NOTFOUND;
6462 DPRINTF(("cursor_next: top page is %"Y"u in cursor %p",
6463 mdb_dbg_pgno(mp), (void *) mc));
6464 if (mc->mc_flags & C_DEL) {
6465 mc->mc_flags ^= C_DEL;
6469 if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
6470 DPUTS("=====> move to next sibling page");
6471 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
6472 mc->mc_flags |= C_EOF;
6475 mp = mc->mc_pg[mc->mc_top];
6476 DPRINTF(("next page is %"Y"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
6478 mc->mc_ki[mc->mc_top]++;
6481 DPRINTF(("==> cursor points to page %"Y"u with %u keys, key index %u",
6482 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
6485 key->mv_size = mc->mc_db->md_pad;
6486 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
6490 mdb_cassert(mc, IS_LEAF(mp));
6491 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6493 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6494 mdb_xcursor_init1(mc, leaf);
6497 if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
6500 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6501 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
6502 if (rc != MDB_SUCCESS)
6507 MDB_GET_KEY(leaf, key);
6511 /** Move the cursor to the previous data item. */
6513 mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
6519 if (!(mc->mc_flags & C_INITIALIZED)) {
6520 rc = mdb_cursor_last(mc, key, data);
6523 mc->mc_ki[mc->mc_top]++;
6526 mp = mc->mc_pg[mc->mc_top];
6528 if (mc->mc_db->md_flags & MDB_DUPSORT) {
6529 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6530 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6531 if (op == MDB_PREV || op == MDB_PREV_DUP) {
6532 rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
6533 if (op != MDB_PREV || rc != MDB_NOTFOUND) {
6534 if (rc == MDB_SUCCESS) {
6535 MDB_GET_KEY(leaf, key);
6536 mc->mc_flags &= ~C_EOF;
6542 MDB_CURSOR_UNREF(&mc->mc_xcursor->mx_cursor, 0);
6545 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6546 if (op == MDB_PREV_DUP)
6547 return MDB_NOTFOUND;
6551 DPRINTF(("cursor_prev: top page is %"Y"u in cursor %p",
6552 mdb_dbg_pgno(mp), (void *) mc));
6554 mc->mc_flags &= ~(C_EOF|C_DEL);
6556 if (mc->mc_ki[mc->mc_top] == 0) {
6557 DPUTS("=====> move to prev sibling page");
6558 if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {
6561 mp = mc->mc_pg[mc->mc_top];
6562 mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1;
6563 DPRINTF(("prev page is %"Y"u, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]));
6565 mc->mc_ki[mc->mc_top]--;
6567 mc->mc_flags &= ~C_EOF;
6569 DPRINTF(("==> cursor points to page %"Y"u with %u keys, key index %u",
6570 mdb_dbg_pgno(mp), NUMKEYS(mp), mc->mc_ki[mc->mc_top]));
6573 key->mv_size = mc->mc_db->md_pad;
6574 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
6578 mdb_cassert(mc, IS_LEAF(mp));
6579 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6581 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6582 mdb_xcursor_init1(mc, leaf);
6585 if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
6588 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6589 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
6590 if (rc != MDB_SUCCESS)
6595 MDB_GET_KEY(leaf, key);
6599 /** Set the cursor on a specific data item. */
6601 mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data,
6602 MDB_cursor_op op, int *exactp)
6606 MDB_node *leaf = NULL;
6609 if (key->mv_size == 0)
6610 return MDB_BAD_VALSIZE;
6613 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6615 /* See if we're already on the right page */
6616 if (mc->mc_flags & C_INITIALIZED) {
6619 mp = mc->mc_pg[mc->mc_top];
6621 mc->mc_ki[mc->mc_top] = 0;
6622 return MDB_NOTFOUND;
6624 if (mp->mp_flags & P_LEAF2) {
6625 nodekey.mv_size = mc->mc_db->md_pad;
6626 nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size);
6628 leaf = NODEPTR(mp, 0);
6629 MDB_GET_KEY2(leaf, nodekey);
6631 rc = mc->mc_dbx->md_cmp(key, &nodekey);
6633 /* Probably happens rarely, but first node on the page
6634 * was the one we wanted.
6636 mc->mc_ki[mc->mc_top] = 0;
6643 unsigned int nkeys = NUMKEYS(mp);
6645 if (mp->mp_flags & P_LEAF2) {
6646 nodekey.mv_data = LEAF2KEY(mp,
6647 nkeys-1, nodekey.mv_size);
6649 leaf = NODEPTR(mp, nkeys-1);
6650 MDB_GET_KEY2(leaf, nodekey);
6652 rc = mc->mc_dbx->md_cmp(key, &nodekey);
6654 /* last node was the one we wanted */
6655 mc->mc_ki[mc->mc_top] = nkeys-1;
6661 if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) {
6662 /* This is definitely the right page, skip search_page */
6663 if (mp->mp_flags & P_LEAF2) {
6664 nodekey.mv_data = LEAF2KEY(mp,
6665 mc->mc_ki[mc->mc_top], nodekey.mv_size);
6667 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6668 MDB_GET_KEY2(leaf, nodekey);
6670 rc = mc->mc_dbx->md_cmp(key, &nodekey);
6672 /* current node was the one we wanted */
6682 /* If any parents have right-sibs, search.
6683 * Otherwise, there's nothing further.
6685 for (i=0; i<mc->mc_top; i++)
6687 NUMKEYS(mc->mc_pg[i])-1)
6689 if (i == mc->mc_top) {
6690 /* There are no other pages */
6691 mc->mc_ki[mc->mc_top] = nkeys;
6692 return MDB_NOTFOUND;
6696 /* There are no other pages */
6697 mc->mc_ki[mc->mc_top] = 0;
6698 if (op == MDB_SET_RANGE && !exactp) {
6702 return MDB_NOTFOUND;
6708 rc = mdb_page_search(mc, key, 0);
6709 if (rc != MDB_SUCCESS)
6712 mp = mc->mc_pg[mc->mc_top];
6713 mdb_cassert(mc, IS_LEAF(mp));
6716 leaf = mdb_node_search(mc, key, exactp);
6717 if (exactp != NULL && !*exactp) {
6718 /* MDB_SET specified and not an exact match. */
6719 return MDB_NOTFOUND;
6723 DPUTS("===> inexact leaf not found, goto sibling");
6724 if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
6725 mc->mc_flags |= C_EOF;
6726 return rc; /* no entries matched */
6728 mp = mc->mc_pg[mc->mc_top];
6729 mdb_cassert(mc, IS_LEAF(mp));
6730 leaf = NODEPTR(mp, 0);
6734 mc->mc_flags |= C_INITIALIZED;
6735 mc->mc_flags &= ~C_EOF;
6738 if (op == MDB_SET_RANGE || op == MDB_SET_KEY) {
6739 key->mv_size = mc->mc_db->md_pad;
6740 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
6746 MDB_CURSOR_UNREF(&mc->mc_xcursor->mx_cursor, 0);
6747 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6748 mdb_xcursor_init1(mc, leaf);
6751 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6752 if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) {
6753 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
6756 if (op == MDB_GET_BOTH) {
6762 rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p);
6763 if (rc != MDB_SUCCESS)
6766 } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
6769 if ((rc = mdb_node_read(mc, leaf, &olddata)) != MDB_SUCCESS)
6771 dcmp = mc->mc_dbx->md_dcmp;
6772 if (NEED_CMP_CLONG(dcmp, olddata.mv_size))
6773 dcmp = mdb_cmp_clong;
6774 rc = dcmp(data, &olddata);
6776 if (op == MDB_GET_BOTH || rc > 0)
6777 return MDB_NOTFOUND;
6784 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6785 if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
6790 /* The key already matches in all other cases */
6791 if (op == MDB_SET_RANGE || op == MDB_SET_KEY)
6792 MDB_GET_KEY(leaf, key);
6793 DPRINTF(("==> cursor placed on key [%s]", DKEY(key)));
6798 /** Move the cursor to the first item in the database. */
6800 mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data)
6805 if (mc->mc_xcursor) {
6806 MDB_CURSOR_UNREF(&mc->mc_xcursor->mx_cursor, 0);
6807 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6810 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
6811 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
6812 if (rc != MDB_SUCCESS)
6815 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
6817 leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0);
6818 mc->mc_flags |= C_INITIALIZED;
6819 mc->mc_flags &= ~C_EOF;
6821 mc->mc_ki[mc->mc_top] = 0;
6823 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6824 key->mv_size = mc->mc_db->md_pad;
6825 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size);
6830 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6831 mdb_xcursor_init1(mc, leaf);
6832 rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL);
6836 if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
6840 MDB_GET_KEY(leaf, key);
6844 /** Move the cursor to the last item in the database. */
6846 mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
6851 if (mc->mc_xcursor) {
6852 MDB_CURSOR_UNREF(&mc->mc_xcursor->mx_cursor, 0);
6853 mc->mc_xcursor->mx_cursor.mc_flags &= ~(C_INITIALIZED|C_EOF);
6856 if (!(mc->mc_flags & C_EOF)) {
6858 if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) {
6859 rc = mdb_page_search(mc, NULL, MDB_PS_LAST);
6860 if (rc != MDB_SUCCESS)
6863 mdb_cassert(mc, IS_LEAF(mc->mc_pg[mc->mc_top]));
6866 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
6867 mc->mc_flags |= C_INITIALIZED|C_EOF;
6868 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
6870 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
6871 key->mv_size = mc->mc_db->md_pad;
6872 key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size);
6877 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6878 mdb_xcursor_init1(mc, leaf);
6879 rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL);
6883 if ((rc = mdb_node_read(mc, leaf, data)) != MDB_SUCCESS)
6888 MDB_GET_KEY(leaf, key);
6893 mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data,
6898 int (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
6903 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
6907 case MDB_GET_CURRENT:
6908 if (!(mc->mc_flags & C_INITIALIZED)) {
6911 MDB_page *mp = mc->mc_pg[mc->mc_top];
6912 int nkeys = NUMKEYS(mp);
6913 if (!nkeys || mc->mc_ki[mc->mc_top] >= nkeys) {
6914 mc->mc_ki[mc->mc_top] = nkeys;
6920 key->mv_size = mc->mc_db->md_pad;
6921 key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size);
6923 MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
6924 MDB_GET_KEY(leaf, key);
6926 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
6927 rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT);
6929 rc = mdb_node_read(mc, leaf, data);
6936 case MDB_GET_BOTH_RANGE:
6941 if (mc->mc_xcursor == NULL) {
6942 rc = MDB_INCOMPATIBLE;
6952 rc = mdb_cursor_set(mc, key, data, op,
6953 op == MDB_SET_RANGE ? NULL : &exact);
6956 case MDB_GET_MULTIPLE:
6957 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
6961 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6962 rc = MDB_INCOMPATIBLE;
6966 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) ||
6967 (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF))
6970 case MDB_NEXT_MULTIPLE:
6975 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
6976 rc = MDB_INCOMPATIBLE;
6979 rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP);
6980 if (rc == MDB_SUCCESS) {
6981 if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) {
6984 mx = &mc->mc_xcursor->mx_cursor;
6985 data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) *
6987 data->mv_data = METADATA(mx->mc_pg[mx->mc_top]);
6988 mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1;
6994 case MDB_PREV_MULTIPLE:
6999 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
7000 rc = MDB_INCOMPATIBLE;
7003 if (!(mc->mc_flags & C_INITIALIZED))
7004 rc = mdb_cursor_last(mc, key, data);
7007 if (rc == MDB_SUCCESS) {
7008 MDB_cursor *mx = &mc->mc_xcursor->mx_cursor;
7009 if (mx->mc_flags & C_INITIALIZED) {
7010 rc = mdb_cursor_sibling(mx, 0);
7011 if (rc == MDB_SUCCESS)
7020 case MDB_NEXT_NODUP:
7021 rc = mdb_cursor_next(mc, key, data, op);
7025 case MDB_PREV_NODUP:
7026 rc = mdb_cursor_prev(mc, key, data, op);
7029 rc = mdb_cursor_first(mc, key, data);
7032 mfunc = mdb_cursor_first;
7034 if (data == NULL || !(mc->mc_flags & C_INITIALIZED)) {
7038 if (mc->mc_xcursor == NULL) {
7039 rc = MDB_INCOMPATIBLE;
7043 MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
7044 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
7045 MDB_GET_KEY(leaf, key);
7046 rc = mdb_node_read(mc, leaf, data);
7050 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
7054 rc = mfunc(&mc->mc_xcursor->mx_cursor, data, NULL);
7057 rc = mdb_cursor_last(mc, key, data);
7060 mfunc = mdb_cursor_last;
7063 DPRINTF(("unhandled/unimplemented cursor operation %u", op));
7068 if (mc->mc_flags & C_DEL)
7069 mc->mc_flags ^= C_DEL;
7074 /** Touch all the pages in the cursor stack. Set mc_top.
7075 * Makes sure all the pages are writable, before attempting a write operation.
7076 * @param[in] mc The cursor to operate on.
7079 mdb_cursor_touch(MDB_cursor *mc)
7081 int rc = MDB_SUCCESS;
7083 if (mc->mc_dbi >= CORE_DBS && !(*mc->mc_dbflag & DB_DIRTY)) {
7086 if (TXN_DBI_CHANGED(mc->mc_txn, mc->mc_dbi))
7088 mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, &mcx);
7089 rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
7092 *mc->mc_dbflag |= DB_DIRTY;
7097 rc = mdb_page_touch(mc);
7098 } while (!rc && ++(mc->mc_top) < mc->mc_snum);
7099 mc->mc_top = mc->mc_snum-1;
7104 /** Do not spill pages to disk if txn is getting full, may fail instead */
7105 #define MDB_NOSPILL 0x8000
7108 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
7112 MDB_node *leaf = NULL;
7113 MDB_page *fp, *mp, *sub_root = NULL;
7115 MDB_val xdata, *rdata, dkey, olddata;
7117 int do_sub = 0, insert_key, insert_data;
7118 unsigned int mcount = 0, dcount = 0, nospill;
7121 unsigned int nflags;
7124 if (mc == NULL || key == NULL)
7127 env = mc->mc_txn->mt_env;
7129 /* Check this first so counter will always be zero on any
7132 if (flags & MDB_MULTIPLE) {
7133 dcount = data[1].mv_size;
7134 data[1].mv_size = 0;
7135 if (!F_ISSET(mc->mc_db->md_flags, MDB_DUPFIXED))
7136 return MDB_INCOMPATIBLE;
7139 nospill = flags & MDB_NOSPILL;
7140 flags &= ~MDB_NOSPILL;
7142 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
7143 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
7145 if (key->mv_size-1 >= ENV_MAXKEY(env))
7146 return MDB_BAD_VALSIZE;
7148 #if SIZE_MAX > MAXDATASIZE
7149 if (data->mv_size > ((mc->mc_db->md_flags & MDB_DUPSORT) ? ENV_MAXKEY(env) : MAXDATASIZE))
7150 return MDB_BAD_VALSIZE;
7152 if ((mc->mc_db->md_flags & MDB_DUPSORT) && data->mv_size > ENV_MAXKEY(env))
7153 return MDB_BAD_VALSIZE;
7156 DPRINTF(("==> put db %d key [%s], size %"Z"u, data size %"Z"u",
7157 DDBI(mc), DKEY(key), key ? key->mv_size : 0, data->mv_size));
7161 if (flags == MDB_CURRENT) {
7162 if (!(mc->mc_flags & C_INITIALIZED))
7165 } else if (mc->mc_db->md_root == P_INVALID) {
7166 /* new database, cursor has nothing to point to */
7169 mc->mc_flags &= ~C_INITIALIZED;
7174 if (flags & MDB_APPEND) {
7176 rc = mdb_cursor_last(mc, &k2, &d2);
7178 rc = mc->mc_dbx->md_cmp(key, &k2);
7181 mc->mc_ki[mc->mc_top]++;
7183 /* new key is <= last key */
7188 rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact);
7190 if ((flags & MDB_NOOVERWRITE) && rc == 0) {
7191 DPRINTF(("duplicate key [%s]", DKEY(key)));
7193 return MDB_KEYEXIST;
7195 if (rc && rc != MDB_NOTFOUND)
7199 if (mc->mc_flags & C_DEL)
7200 mc->mc_flags ^= C_DEL;
7202 /* Cursor is positioned, check for room in the dirty list */
7204 if (flags & MDB_MULTIPLE) {
7206 xdata.mv_size = data->mv_size * dcount;
7210 if ((rc2 = mdb_page_spill(mc, key, rdata)))
7214 if (rc == MDB_NO_ROOT) {
7216 /* new database, write a root leaf page */
7217 DPUTS("allocating new root leaf page");
7218 if ((rc2 = mdb_page_new(mc, P_LEAF, 1, &np))) {
7221 mdb_cursor_push(mc, np);
7222 mc->mc_db->md_root = np->mp_pgno;
7223 mc->mc_db->md_depth++;
7224 *mc->mc_dbflag |= DB_DIRTY;
7225 if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED))
7227 np->mp_flags |= P_LEAF2;
7228 mc->mc_flags |= C_INITIALIZED;
7230 /* make sure all cursor pages are writable */
7231 rc2 = mdb_cursor_touch(mc);
7236 insert_key = insert_data = rc;
7238 /* The key does not exist */
7239 DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
7240 if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
7241 LEAFSIZE(key, data) > env->me_nodemax)
7243 /* Too big for a node, insert in sub-DB. Set up an empty
7244 * "old sub-page" for prep_subDB to expand to a full page.
7246 fp_flags = P_LEAF|P_DIRTY;
7248 fp->mp_pad = data->mv_size; /* used if MDB_DUPFIXED */
7249 fp->mp_lower = fp->mp_upper = (PAGEHDRSZ-PAGEBASE);
7250 olddata.mv_size = PAGEHDRSZ;
7254 /* there's only a key anyway, so this is a no-op */
7255 if (IS_LEAF2(mc->mc_pg[mc->mc_top])) {
7257 unsigned int ksize = mc->mc_db->md_pad;
7258 if (key->mv_size != ksize)
7259 return MDB_BAD_VALSIZE;
7260 ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize);
7261 memcpy(ptr, key->mv_data, ksize);
7263 /* if overwriting slot 0 of leaf, need to
7264 * update branch key if there is a parent page
7266 if (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
7267 unsigned short dtop = 1;
7269 /* slot 0 is always an empty key, find real slot */
7270 while (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
7274 if (mc->mc_ki[mc->mc_top])
7275 rc2 = mdb_update_key(mc, key);
7286 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
7287 olddata.mv_size = NODEDSZ(leaf);
7288 olddata.mv_data = NODEDATA(leaf);
7291 if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
7292 /* Prepare (sub-)page/sub-DB to accept the new item,
7293 * if needed. fp: old sub-page or a header faking
7294 * it. mp: new (sub-)page. offset: growth in page
7295 * size. xdata: node data with new page or DB.
7297 unsigned i, offset = 0;
7298 mp = fp = xdata.mv_data = env->me_pbuf;
7299 mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
7301 /* Was a single item before, must convert now */
7302 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
7304 /* Just overwrite the current item */
7305 if (flags == MDB_CURRENT)
7307 dcmp = mc->mc_dbx->md_dcmp;
7308 if (NEED_CMP_CLONG(dcmp, olddata.mv_size))
7309 dcmp = mdb_cmp_clong;
7310 /* does data match? */
7311 if (!dcmp(data, &olddata)) {
7312 if (flags & (MDB_NODUPDATA|MDB_APPENDDUP))
7313 return MDB_KEYEXIST;
7318 /* Back up original data item */
7319 dkey.mv_size = olddata.mv_size;
7320 dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);
7322 /* Make sub-page header for the dup items, with dummy body */
7323 fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
7324 fp->mp_lower = (PAGEHDRSZ-PAGEBASE);
7325 xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;
7326 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
7327 fp->mp_flags |= P_LEAF2;
7328 fp->mp_pad = data->mv_size;
7329 xdata.mv_size += 2 * data->mv_size; /* leave space for 2 more */
7331 xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +
7332 (dkey.mv_size & 1) + (data->mv_size & 1);
7334 fp->mp_upper = xdata.mv_size - PAGEBASE;
7335 olddata.mv_size = xdata.mv_size; /* pretend olddata is fp */
7336 } else if (leaf->mn_flags & F_SUBDATA) {
7337 /* Data is on sub-DB, just store it */
7338 flags |= F_DUPDATA|F_SUBDATA;
7341 /* Data is on sub-page */
7342 fp = olddata.mv_data;
7345 if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
7346 offset = EVEN(NODESIZE + sizeof(indx_t) +
7350 offset = fp->mp_pad;
7351 if (SIZELEFT(fp) < offset) {
7352 offset *= 4; /* space for 4 more */
7355 /* FALLTHRU: Big enough MDB_DUPFIXED sub-page */
7357 fp->mp_flags |= P_DIRTY;
7358 COPY_PGNO(fp->mp_pgno, mp->mp_pgno);
7359 mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
7363 xdata.mv_size = olddata.mv_size + offset;
7366 fp_flags = fp->mp_flags;
7367 if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {
7368 /* Too big for a sub-page, convert to sub-DB */
7369 fp_flags &= ~P_SUBP;
7371 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
7372 fp_flags |= P_LEAF2;
7373 dummy.md_pad = fp->mp_pad;
7374 dummy.md_flags = MDB_DUPFIXED;
7375 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
7376 dummy.md_flags |= MDB_INTEGERKEY;
7382 dummy.md_branch_pages = 0;
7383 dummy.md_leaf_pages = 1;
7384 dummy.md_overflow_pages = 0;
7385 dummy.md_entries = NUMKEYS(fp);
7386 xdata.mv_size = sizeof(MDB_db);
7387 xdata.mv_data = &dummy;
7388 if ((rc = mdb_page_alloc(mc, 1, &mp)))
7390 offset = env->me_psize - olddata.mv_size;
7391 flags |= F_DUPDATA|F_SUBDATA;
7392 dummy.md_root = mp->mp_pgno;
7396 mp->mp_flags = fp_flags | P_DIRTY;
7397 mp->mp_pad = fp->mp_pad;
7398 mp->mp_lower = fp->mp_lower;
7399 mp->mp_upper = fp->mp_upper + offset;
7400 if (fp_flags & P_LEAF2) {
7401 memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
7403 memcpy((char *)mp + mp->mp_upper + PAGEBASE, (char *)fp + fp->mp_upper + PAGEBASE,
7404 olddata.mv_size - fp->mp_upper - PAGEBASE);
7405 for (i=0; i<NUMKEYS(fp); i++)
7406 mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
7414 mdb_node_del(mc, 0);
7418 /* LMDB passes F_SUBDATA in 'flags' to write a DB record */
7419 if ((leaf->mn_flags ^ flags) & F_SUBDATA)
7420 return MDB_INCOMPATIBLE;
7421 /* overflow page overwrites need special handling */
7422 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
7425 int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
7427 memcpy(&pg, olddata.mv_data, sizeof(pg));
7428 if ((rc2 = mdb_page_get(mc, pg, &omp, &level)) != 0)
7430 ovpages = omp->mp_pages;
7432 /* Is the ov page large enough? */
7433 if (ovpages >= dpages) {
7434 if (!(omp->mp_flags & P_DIRTY) &&
7435 (level || (env->me_flags & MDB_WRITEMAP)))
7437 rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
7440 level = 0; /* dirty in this txn or clean */
7443 if (omp->mp_flags & P_DIRTY) {
7444 /* yes, overwrite it. Note in this case we don't
7445 * bother to try shrinking the page if the new data
7446 * is smaller than the overflow threshold.
7449 /* It is writable only in a parent txn */
7450 size_t sz = (size_t) env->me_psize * ovpages, off;
7451 MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
7457 /* Note - this page is already counted in parent's dirty_room */
7458 rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
7459 mdb_cassert(mc, rc2 == 0);
7460 /* Currently we make the page look as with put() in the
7461 * parent txn, in case the user peeks at MDB_RESERVEd
7462 * or unused parts. Some users treat ovpages specially.
7464 if (!(flags & MDB_RESERVE)) {
7465 /* Skip the part where LMDB will put *data.
7466 * Copy end of page, adjusting alignment so
7467 * compiler may copy words instead of bytes.
7469 off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
7470 memcpy((size_t *)((char *)np + off),
7471 (size_t *)((char *)omp + off), sz - off);
7474 memcpy(np, omp, sz); /* Copy beginning of page */
7477 SETDSZ(leaf, data->mv_size);
7478 if (F_ISSET(flags, MDB_RESERVE))
7479 data->mv_data = METADATA(omp);
7481 memcpy(METADATA(omp), data->mv_data, data->mv_size);
7485 if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
7487 } else if (data->mv_size == olddata.mv_size) {
7488 /* same size, just replace it. Note that we could
7489 * also reuse this node if the new data is smaller,
7490 * but instead we opt to shrink the node in that case.
7492 if (F_ISSET(flags, MDB_RESERVE))
7493 data->mv_data = olddata.mv_data;
7494 else if (!(mc->mc_flags & C_SUB))
7495 memcpy(olddata.mv_data, data->mv_data, data->mv_size);
7497 memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
7502 mdb_node_del(mc, 0);
7508 nflags = flags & NODE_ADD_FLAGS;
7509 nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);
7510 if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
7511 if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
7512 nflags &= ~MDB_APPEND; /* sub-page may need room to grow */
7514 nflags |= MDB_SPLIT_REPLACE;
7515 rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
7517 /* There is room already in this leaf page. */
7518 rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
7520 /* Adjust other cursors pointing to mp */
7521 MDB_cursor *m2, *m3;
7522 MDB_dbi dbi = mc->mc_dbi;
7523 unsigned i = mc->mc_top;
7524 MDB_page *mp = mc->mc_pg[i];
7526 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
7527 if (mc->mc_flags & C_SUB)
7528 m3 = &m2->mc_xcursor->mx_cursor;
7531 if (m3 == mc || m3->mc_snum < mc->mc_snum || m3->mc_pg[i] != mp) continue;
7532 if (m3->mc_ki[i] >= mc->mc_ki[i] && insert_key) {
7535 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
7536 MDB_node *n2 = NODEPTR(mp, m3->mc_ki[i]);
7537 if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
7538 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
7544 if (rc == MDB_SUCCESS) {
7545 /* Now store the actual data in the child DB. Note that we're
7546 * storing the user data in the keys field, so there are strict
7547 * size limits on dupdata. The actual data fields of the child
7548 * DB are all zero size.
7551 int xflags, new_dupdata;
7556 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
7557 if (flags & MDB_CURRENT) {
7558 xflags = MDB_CURRENT|MDB_NOSPILL;
7560 mdb_xcursor_init1(mc, leaf);
7561 xflags = (flags & MDB_NODUPDATA) ?
7562 MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
7565 mc->mc_xcursor->mx_cursor.mc_pg[0] = sub_root;
7566 new_dupdata = (int)dkey.mv_size;
7567 /* converted, write the original data first */
7569 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
7572 /* we've done our job */
7575 if (!(leaf->mn_flags & F_SUBDATA) || sub_root) {
7576 /* Adjust other cursors pointing to mp */
7578 MDB_xcursor *mx = mc->mc_xcursor;
7579 unsigned i = mc->mc_top;
7580 MDB_page *mp = mc->mc_pg[i];
7581 int nkeys = NUMKEYS(mp);
7583 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
7584 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
7585 if (!(m2->mc_flags & C_INITIALIZED)) continue;
7586 if (m2->mc_pg[i] == mp) {
7587 if (m2->mc_ki[i] == mc->mc_ki[i]) {
7588 mdb_xcursor_init2(m2, mx, new_dupdata);
7589 } else if (!insert_key && m2->mc_ki[i] < nkeys) {
7590 MDB_node *n2 = NODEPTR(mp, m2->mc_ki[i]);
7591 if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
7592 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
7597 ecount = mc->mc_xcursor->mx_db.md_entries;
7598 if (flags & MDB_APPENDDUP)
7599 xflags |= MDB_APPEND;
7600 rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
7601 if (flags & F_SUBDATA) {
7602 void *db = NODEDATA(leaf);
7603 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
7605 insert_data = mc->mc_xcursor->mx_db.md_entries - ecount;
7607 /* Increment count unless we just replaced an existing item. */
7609 mc->mc_db->md_entries++;
7611 /* Invalidate txn if we created an empty sub-DB */
7614 /* If we succeeded and the key didn't exist before,
7615 * make sure the cursor is marked valid.
7617 mc->mc_flags |= C_INITIALIZED;
7619 if (flags & MDB_MULTIPLE) {
7622 /* let caller know how many succeeded, if any */
7623 data[1].mv_size = mcount;
7624 if (mcount < dcount) {
7625 data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
7626 insert_key = insert_data = 0;
7633 if (rc == MDB_KEYEXIST) /* should not happen, we deleted that item */
7636 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7641 mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
7647 if (mc->mc_txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
7648 return (mc->mc_txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
7650 if (!(mc->mc_flags & C_INITIALIZED))
7653 if (mc->mc_ki[mc->mc_top] >= NUMKEYS(mc->mc_pg[mc->mc_top]))
7654 return MDB_NOTFOUND;
7656 if (!(flags & MDB_NOSPILL) && (rc = mdb_page_spill(mc, NULL, NULL)))
7659 rc = mdb_cursor_touch(mc);
7663 mp = mc->mc_pg[mc->mc_top];
7666 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
7668 if (F_ISSET(leaf->mn_flags, F_DUPDATA)) {
7669 if (flags & MDB_NODUPDATA) {
7670 /* mdb_cursor_del0() will subtract the final entry */
7671 mc->mc_db->md_entries -= mc->mc_xcursor->mx_db.md_entries - 1;
7672 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
7674 if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) {
7675 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
7677 rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, MDB_NOSPILL);
7680 /* If sub-DB still has entries, we're done */
7681 if (mc->mc_xcursor->mx_db.md_entries) {
7682 if (leaf->mn_flags & F_SUBDATA) {
7683 /* update subDB info */
7684 void *db = NODEDATA(leaf);
7685 memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
7688 /* shrink fake page */
7689 mdb_node_shrink(mp, mc->mc_ki[mc->mc_top]);
7690 leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
7691 mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
7692 /* fix other sub-DB cursors pointed at fake pages on this page */
7693 for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
7694 if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
7695 if (!(m2->mc_flags & C_INITIALIZED)) continue;
7696 if (m2->mc_pg[mc->mc_top] == mp) {
7697 if (m2->mc_ki[mc->mc_top] == mc->mc_ki[mc->mc_top]) {
7698 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf);
7700 MDB_node *n2 = NODEPTR(mp, m2->mc_ki[mc->mc_top]);
7701 if (!(n2->mn_flags & F_SUBDATA))
7702 m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
7707 mc->mc_db->md_entries--;
7710 mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
7712 /* otherwise fall thru and delete the sub-DB */
7715 if (leaf->mn_flags & F_SUBDATA) {
7716 /* add all the child DB's pages to the free list */
7717 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
7722 /* LMDB passes F_SUBDATA in 'flags' to delete a DB record */
7723 else if ((leaf->mn_flags ^ flags) & F_SUBDATA) {
7724 rc = MDB_INCOMPATIBLE;
7728 /* add overflow pages to free list */
7729 if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
7733 memcpy(&pg, NODEDATA(leaf), sizeof(pg));
7734 if ((rc = mdb_page_get(mc, pg, &omp, NULL)) ||
7735 (rc = mdb_ovpage_free(mc, omp)))
7740 return mdb_cursor_del0(mc);
7743 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7747 /** Allocate and initialize new pages for a database.
7748 * @param[in] mc a cursor on the database being added to.
7749 * @param[in] flags flags defining what type of page is being allocated.
7750 * @param[in] num the number of pages to allocate. This is usually 1,
7751 * unless allocating overflow pages for a large record.
7752 * @param[out] mp Address of a page, or NULL on failure.
7753 * @return 0 on success, non-zero on failure.
7756 mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp)
7761 if ((rc = mdb_page_alloc(mc, num, &np)))
7763 DPRINTF(("allocated new mpage %"Y"u, page size %u",
7764 np->mp_pgno, mc->mc_txn->mt_env->me_psize));
7765 np->mp_flags = flags | P_DIRTY;
7766 np->mp_lower = (PAGEHDRSZ-PAGEBASE);
7767 np->mp_upper = mc->mc_txn->mt_env->me_psize - PAGEBASE;
7770 mc->mc_db->md_branch_pages++;
7771 else if (IS_LEAF(np))
7772 mc->mc_db->md_leaf_pages++;
7773 else if (IS_OVERFLOW(np)) {
7774 mc->mc_db->md_overflow_pages += num;
7782 /** Calculate the size of a leaf node.
7783 * The size depends on the environment's page size; if a data item
7784 * is too large it will be put onto an overflow page and the node
7785 * size will only include the key and not the data. Sizes are always
7786 * rounded up to an even number of bytes, to guarantee 2-byte alignment
7787 * of the #MDB_node headers.
7788 * @param[in] env The environment handle.
7789 * @param[in] key The key for the node.
7790 * @param[in] data The data for the node.
7791 * @return The number of bytes needed to store the node.
7794 mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data)
7798 sz = LEAFSIZE(key, data);
7799 if (sz > env->me_nodemax) {
7800 /* put on overflow page */
7801 sz -= data->mv_size - sizeof(pgno_t);
7804 return EVEN(sz + sizeof(indx_t));
7807 /** Calculate the size of a branch node.
7808 * The size should depend on the environment's page size but since
7809 * we currently don't support spilling large keys onto overflow
7810 * pages, it's simply the size of the #MDB_node header plus the
7811 * size of the key. Sizes are always rounded up to an even number
7812 * of bytes, to guarantee 2-byte alignment of the #MDB_node headers.
7813 * @param[in] env The environment handle.
7814 * @param[in] key The key for the node.
7815 * @return The number of bytes needed to store the node.
7818 mdb_branch_size(MDB_env *env, MDB_val *key)
7823 if (sz > env->me_nodemax) {
7824 /* put on overflow page */
7825 /* not implemented */
7826 /* sz -= key->size - sizeof(pgno_t); */
7829 return sz + sizeof(indx_t);
7832 /** Add a node to the page pointed to by the cursor.
7833 * @param[in] mc The cursor for this operation.
7834 * @param[in] indx The index on the page where the new node should be added.
7835 * @param[in] key The key for the new node.
7836 * @param[in] data The data for the new node, if any.
7837 * @param[in] pgno The page number, if adding a branch node.
7838 * @param[in] flags Flags for the node.
7839 * @return 0 on success, non-zero on failure. Possible errors are:
7841 * <li>ENOMEM - failed to allocate overflow pages for the node.
7842 * <li>MDB_PAGE_FULL - there is insufficient room in the page. This error
7843 * should never happen since all callers already calculate the
7844 * page's free space before calling this function.
7848 mdb_node_add(MDB_cursor *mc, indx_t indx,
7849 MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags)
7852 size_t node_size = NODESIZE;
7856 MDB_page *mp = mc->mc_pg[mc->mc_top];
7857 MDB_page *ofp = NULL; /* overflow page */
7861 mdb_cassert(mc, mp->mp_upper >= mp->mp_lower);
7863 DPRINTF(("add to %s %spage %"Y"u index %i, data size %"Z"u key size %"Z"u [%s]",
7864 IS_LEAF(mp) ? "leaf" : "branch",
7865 IS_SUBP(mp) ? "sub-" : "",
7866 mdb_dbg_pgno(mp), indx, data ? data->mv_size : 0,
7867 key ? key->mv_size : 0, key ? DKEY(key) : "null"));
7870 /* Move higher keys up one slot. */
7871 int ksize = mc->mc_db->md_pad, dif;
7872 char *ptr = LEAF2KEY(mp, indx, ksize);
7873 dif = NUMKEYS(mp) - indx;
7875 memmove(ptr+ksize, ptr, dif*ksize);
7876 /* insert new key */
7877 memcpy(ptr, key->mv_data, ksize);
7879 /* Just using these for counting */
7880 mp->mp_lower += sizeof(indx_t);
7881 mp->mp_upper -= ksize - sizeof(indx_t);
7885 room = (ssize_t)SIZELEFT(mp) - (ssize_t)sizeof(indx_t);
7887 node_size += key->mv_size;
7889 mdb_cassert(mc, key && data);
7890 if (F_ISSET(flags, F_BIGDATA)) {
7891 /* Data already on overflow page. */
7892 node_size += sizeof(pgno_t);
7893 } else if (node_size + data->mv_size > mc->mc_txn->mt_env->me_nodemax) {
7894 int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize);
7896 /* Put data on overflow page. */
7897 DPRINTF(("data size is %"Z"u, node would be %"Z"u, put data on overflow page",
7898 data->mv_size, node_size+data->mv_size));
7899 node_size = EVEN(node_size + sizeof(pgno_t));
7900 if ((ssize_t)node_size > room)
7902 if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp)))
7904 DPRINTF(("allocated overflow page %"Y"u", ofp->mp_pgno));
7908 node_size += data->mv_size;
7911 node_size = EVEN(node_size);
7912 if ((ssize_t)node_size > room)
7916 /* Move higher pointers up one slot. */
7917 for (i = NUMKEYS(mp); i > indx; i--)
7918 mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
7920 /* Adjust free space offsets. */
7921 ofs = mp->mp_upper - node_size;
7922 mdb_cassert(mc, ofs >= mp->mp_lower + sizeof(indx_t));
7923 mp->mp_ptrs[indx] = ofs;
7925 mp->mp_lower += sizeof(indx_t);
7927 /* Write the node data. */
7928 node = NODEPTR(mp, indx);
7929 node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
7930 node->mn_flags = flags;
7932 SETDSZ(node,data->mv_size);
7937 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
7940 ndata = NODEDATA(node);
7942 if (F_ISSET(flags, F_BIGDATA))
7943 memcpy(ndata, data->mv_data, sizeof(pgno_t));
7944 else if (F_ISSET(flags, MDB_RESERVE))
7945 data->mv_data = ndata;
7947 memcpy(ndata, data->mv_data, data->mv_size);
7949 memcpy(ndata, &ofp->mp_pgno, sizeof(pgno_t));
7950 ndata = METADATA(ofp);
7951 if (F_ISSET(flags, MDB_RESERVE))
7952 data->mv_data = ndata;
7954 memcpy(ndata, data->mv_data, data->mv_size);
7961 DPRINTF(("not enough room in page %"Y"u, got %u ptrs",
7962 mdb_dbg_pgno(mp), NUMKEYS(mp)));
7963 DPRINTF(("upper-lower = %u - %u = %"Z"d", mp->mp_upper,mp->mp_lower,room));
7964 DPRINTF(("node size = %"Z"u", node_size));
7965 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
7966 return MDB_PAGE_FULL;
7969 /** Delete the specified node from a page.
7970 * @param[in] mc Cursor pointing to the node to delete.
7971 * @param[in] ksize The size of a node. Only used if the page is
7972 * part of a #MDB_DUPFIXED database.
7975 mdb_node_del(MDB_cursor *mc, int ksize)
7977 MDB_page *mp = mc->mc_pg[mc->mc_top];
7978 indx_t indx = mc->mc_ki[mc->mc_top];
7980 indx_t i, j, numkeys, ptr;
7984 DPRINTF(("delete node %u on %s page %"Y"u", indx,
7985 IS_LEAF(mp) ? "leaf" : "branch", mdb_dbg_pgno(mp)));
7986 numkeys = NUMKEYS(mp);
7987 mdb_cassert(mc, indx < numkeys);
7990 int x = numkeys - 1 - indx;
7991 base = LEAF2KEY(mp, indx, ksize);
7993 memmove(base, base + ksize, x * ksize);
7994 mp->mp_lower -= sizeof(indx_t);
7995 mp->mp_upper += ksize - sizeof(indx_t);
7999 node = NODEPTR(mp, indx);
8000 sz = NODESIZE + node->mn_ksize;
8002 if (F_ISSET(node->mn_flags, F_BIGDATA))
8003 sz += sizeof(pgno_t);
8005 sz += NODEDSZ(node);
8009 ptr = mp->mp_ptrs[indx];
8010 for (i = j = 0; i < numkeys; i++) {
8012 mp->mp_ptrs[j] = mp->mp_ptrs[i];
8013 if (mp->mp_ptrs[i] < ptr)
8014 mp->mp_ptrs[j] += sz;
8019 base = (char *)mp + mp->mp_upper + PAGEBASE;
8020 memmove(base + sz, base, ptr - mp->mp_upper);
8022 mp->mp_lower -= sizeof(indx_t);
8026 /** Compact the main page after deleting a node on a subpage.
8027 * @param[in] mp The main page to operate on.
8028 * @param[in] indx The index of the subpage on the main page.
8031 mdb_node_shrink(MDB_page *mp, indx_t indx)
8036 indx_t delta, nsize, len, ptr;
8039 node = NODEPTR(mp, indx);
8040 sp = (MDB_page *)NODEDATA(node);
8041 delta = SIZELEFT(sp);
8042 nsize = NODEDSZ(node) - delta;
8044 /* Prepare to shift upward, set len = length(subpage part to shift) */
8048 return; /* do not make the node uneven-sized */
8050 xp = (MDB_page *)((char *)sp + delta); /* destination subpage */
8051 for (i = NUMKEYS(sp); --i >= 0; )
8052 xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
8055 sp->mp_upper = sp->mp_lower;
8056 COPY_PGNO(sp->mp_pgno, mp->mp_pgno);
8057 SETDSZ(node, nsize);
8059 /* Shift <lower nodes...initial part of subpage> upward */
8060 base = (char *)mp + mp->mp_upper + PAGEBASE;
8061 memmove(base + delta, base, (char *)sp + len - base);
8063 ptr = mp->mp_ptrs[indx];
8064 for (i = NUMKEYS(mp); --i >= 0; ) {
8065 if (mp->mp_ptrs[i] <= ptr)
8066 mp->mp_ptrs[i] += delta;
8068 mp->mp_upper += delta;
8071 /** Initial setup of a sorted-dups cursor.
8072 * Sorted duplicates are implemented as a sub-database for the given key.
8073 * The duplicate data items are actually keys of the sub-database.
8074 * Operations on the duplicate data items are performed using a sub-cursor
8075 * initialized when the sub-database is first accessed. This function does
8076 * the preliminary setup of the sub-cursor, filling in the fields that
8077 * depend only on the parent DB.
8078 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
8081 mdb_xcursor_init0(MDB_cursor *mc)
8083 MDB_xcursor *mx = mc->mc_xcursor;
8085 mx->mx_cursor.mc_xcursor = NULL;
8086 mx->mx_cursor.mc_txn = mc->mc_txn;
8087 mx->mx_cursor.mc_db = &mx->mx_db;
8088 mx->mx_cursor.mc_dbx = &mx->mx_dbx;
8089 mx->mx_cursor.mc_dbi = mc->mc_dbi;
8090 mx->mx_cursor.mc_dbflag = &mx->mx_dbflag;
8091 mx->mx_cursor.mc_snum = 0;
8092 mx->mx_cursor.mc_top = 0;
8093 MC_SET_OVPG(&mx->mx_cursor, NULL);
8094 mx->mx_cursor.mc_flags = C_SUB | (mc->mc_flags & (C_ORIG_RDONLY|C_WRITEMAP));
8095 mx->mx_dbx.md_name.mv_size = 0;
8096 mx->mx_dbx.md_name.mv_data = NULL;
8097 mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp;
8098 mx->mx_dbx.md_dcmp = NULL;
8099 mx->mx_dbx.md_rel = mc->mc_dbx->md_rel;
8102 /** Final setup of a sorted-dups cursor.
8103 * Sets up the fields that depend on the data from the main cursor.
8104 * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized.
8105 * @param[in] node The data containing the #MDB_db record for the
8106 * sorted-dup database.
8109 mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node)
8111 MDB_xcursor *mx = mc->mc_xcursor;
8113 mx->mx_cursor.mc_flags &= C_SUB|C_ORIG_RDONLY|C_WRITEMAP;
8114 if (node->mn_flags & F_SUBDATA) {
8115 memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db));
8116 mx->mx_cursor.mc_pg[0] = 0;
8117 mx->mx_cursor.mc_snum = 0;
8118 mx->mx_cursor.mc_top = 0;
8120 MDB_page *fp = NODEDATA(node);
8121 mx->mx_db.md_pad = 0;
8122 mx->mx_db.md_flags = 0;
8123 mx->mx_db.md_depth = 1;
8124 mx->mx_db.md_branch_pages = 0;
8125 mx->mx_db.md_leaf_pages = 1;
8126 mx->mx_db.md_overflow_pages = 0;
8127 mx->mx_db.md_entries = NUMKEYS(fp);
8128 COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno);
8129 mx->mx_cursor.mc_snum = 1;
8130 mx->mx_cursor.mc_top = 0;
8131 mx->mx_cursor.mc_flags |= C_INITIALIZED;
8132 mx->mx_cursor.mc_pg[0] = fp;
8133 mx->mx_cursor.mc_ki[0] = 0;
8134 if (mc->mc_db->md_flags & MDB_DUPFIXED) {
8135 mx->mx_db.md_flags = MDB_DUPFIXED;
8136 mx->mx_db.md_pad = fp->mp_pad;
8137 if (mc->mc_db->md_flags & MDB_INTEGERDUP)
8138 mx->mx_db.md_flags |= MDB_INTEGERKEY;
8141 DPRINTF(("Sub-db -%u root page %"Y"u", mx->mx_cursor.mc_dbi,
8142 mx->mx_db.md_root));
8143 mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
8144 if (NEED_CMP_CLONG(mx->mx_dbx.md_cmp, mx->mx_db.md_pad))
8145 mx->mx_dbx.md_cmp = mdb_cmp_clong;
8149 /** Fixup a sorted-dups cursor due to underlying update.
8150 * Sets up some fields that depend on the data from the main cursor.
8151 * Almost the same as init1, but skips initialization steps if the
8152 * xcursor had already been used.
8153 * @param[in] mc The main cursor whose sorted-dups cursor is to be fixed up.
8154 * @param[in] src_mx The xcursor of an up-to-date cursor.
8155 * @param[in] new_dupdata True if converting from a non-#F_DUPDATA item.
8158 mdb_xcursor_init2(MDB_cursor *mc, MDB_xcursor *src_mx, int new_dupdata)
8160 MDB_xcursor *mx = mc->mc_xcursor;
8163 mx->mx_cursor.mc_snum = 1;
8164 mx->mx_cursor.mc_top = 0;
8165 mx->mx_cursor.mc_flags |= C_INITIALIZED;
8166 mx->mx_cursor.mc_ki[0] = 0;
8167 mx->mx_dbflag = DB_VALID|DB_USRVALID|DB_DIRTY; /* DB_DIRTY guides mdb_cursor_touch */
8168 #if UINT_MAX < MDB_SIZE_MAX /* matches mdb_xcursor_init1:NEED_CMP_CLONG() */
8169 mx->mx_dbx.md_cmp = src_mx->mx_dbx.md_cmp;
8171 } else if (!(mx->mx_cursor.mc_flags & C_INITIALIZED)) {
8174 mx->mx_db = src_mx->mx_db;
8175 mx->mx_cursor.mc_pg[0] = src_mx->mx_cursor.mc_pg[0];
8176 DPRINTF(("Sub-db -%u root page %"Y"u", mx->mx_cursor.mc_dbi,
8177 mx->mx_db.md_root));
8180 /** Initialize a cursor for a given transaction and database. */
8182 mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
8185 mc->mc_backup = NULL;
8188 mc->mc_db = &txn->mt_dbs[dbi];
8189 mc->mc_dbx = &txn->mt_dbxs[dbi];
8190 mc->mc_dbflag = &txn->mt_dbflags[dbi];
8195 MC_SET_OVPG(mc, NULL);
8196 mc->mc_flags = txn->mt_flags & (C_ORIG_RDONLY|C_WRITEMAP);
8197 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
8198 mdb_tassert(txn, mx != NULL);
8199 mc->mc_xcursor = mx;
8200 mdb_xcursor_init0(mc);
8202 mc->mc_xcursor = NULL;
8204 if (*mc->mc_dbflag & DB_STALE) {
8205 mdb_page_search(mc, NULL, MDB_PS_ROOTONLY);
8210 mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret)
8213 size_t size = sizeof(MDB_cursor);
8215 if (!ret || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
8218 if (txn->mt_flags & MDB_TXN_BLOCKED)
8221 if (dbi == FREE_DBI && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
8224 if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT)
8225 size += sizeof(MDB_xcursor);
8227 if ((mc = malloc(size)) != NULL) {
8228 mdb_cursor_init(mc, txn, dbi, (MDB_xcursor *)(mc + 1));
8229 if (txn->mt_cursors) {
8230 mc->mc_next = txn->mt_cursors[dbi];
8231 txn->mt_cursors[dbi] = mc;
8232 mc->mc_flags |= C_UNTRACK;
8244 mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc)
8246 if (!mc || !TXN_DBI_EXIST(txn, mc->mc_dbi, DB_VALID))
8249 if ((mc->mc_flags & C_UNTRACK) || txn->mt_cursors)
8252 if (txn->mt_flags & MDB_TXN_BLOCKED)
8255 mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor);
8259 /* Return the count of duplicate data items for the current key */
8261 mdb_cursor_count(MDB_cursor *mc, mdb_size_t *countp)
8265 if (mc == NULL || countp == NULL)
8268 if (mc->mc_xcursor == NULL)
8269 return MDB_INCOMPATIBLE;
8271 if (mc->mc_txn->mt_flags & MDB_TXN_BLOCKED)
8274 if (!(mc->mc_flags & C_INITIALIZED))
8277 if (!mc->mc_snum || (mc->mc_flags & C_EOF))
8278 return MDB_NOTFOUND;
8280 leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
8281 if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
8284 if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED))
8287 *countp = mc->mc_xcursor->mx_db.md_entries;
8293 mdb_cursor_close(MDB_cursor *mc)
8295 if (mc && !mc->mc_backup) {
8296 /* remove from txn, if tracked */
8297 if ((mc->mc_flags & C_UNTRACK) && mc->mc_txn->mt_cursors) {
8298 MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi];
8299 while (*prev && *prev != mc) prev = &(*prev)->mc_next;
8301 *prev = mc->mc_next;
8308 mdb_cursor_txn(MDB_cursor *mc)
8310 if (!mc) return NULL;
8315 mdb_cursor_dbi(MDB_cursor *mc)
8320 /** Replace the key for a branch node with a new key.
8321 * @param[in] mc Cursor pointing to the node to operate on.
8322 * @param[in] key The new key to use.
8323 * @return 0 on success, non-zero on failure.
8326 mdb_update_key(MDB_cursor *mc, MDB_val *key)
8332 int delta, ksize, oksize;
8333 indx_t ptr, i, numkeys, indx;
8336 indx = mc->mc_ki[mc->mc_top];
8337 mp = mc->mc_pg[mc->mc_top];
8338 node = NODEPTR(mp, indx);
8339 ptr = mp->mp_ptrs[indx];
8343 char kbuf2[DKBUF_MAXKEYSIZE*2+1];
8344 k2.mv_data = NODEKEY(node);
8345 k2.mv_size = node->mn_ksize;
8346 DPRINTF(("update key %u (ofs %u) [%s] to [%s] on page %"Y"u",
8348 mdb_dkey(&k2, kbuf2),
8354 /* Sizes must be 2-byte aligned. */
8355 ksize = EVEN(key->mv_size);
8356 oksize = EVEN(node->mn_ksize);
8357 delta = ksize - oksize;
8359 /* Shift node contents if EVEN(key length) changed. */
8361 if (delta > 0 && SIZELEFT(mp) < delta) {
8363 /* not enough space left, do a delete and split */
8364 DPRINTF(("Not enough room, delta = %d, splitting...", delta));
8365 pgno = NODEPGNO(node);
8366 mdb_node_del(mc, 0);
8367 return mdb_page_split(mc, key, NULL, pgno, MDB_SPLIT_REPLACE);
8370 numkeys = NUMKEYS(mp);
8371 for (i = 0; i < numkeys; i++) {
8372 if (mp->mp_ptrs[i] <= ptr)
8373 mp->mp_ptrs[i] -= delta;
8376 base = (char *)mp + mp->mp_upper + PAGEBASE;
8377 len = ptr - mp->mp_upper + NODESIZE;
8378 memmove(base - delta, base, len);
8379 mp->mp_upper -= delta;
8381 node = NODEPTR(mp, indx);
8384 /* But even if no shift was needed, update ksize */
8385 if (node->mn_ksize != key->mv_size)
8386 node->mn_ksize = key->mv_size;
8389 memcpy(NODEKEY(node), key->mv_data, key->mv_size);
8395 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
8397 /** Perform \b act while tracking temporary cursor \b mn */
8398 #define WITH_CURSOR_TRACKING(mn, act) do { \
8399 MDB_cursor dummy, *tracked, **tp = &(mn).mc_txn->mt_cursors[mn.mc_dbi]; \
8400 if ((mn).mc_flags & C_SUB) { \
8401 dummy.mc_flags = C_INITIALIZED; \
8402 dummy.mc_xcursor = (MDB_xcursor *)&(mn); \
8407 tracked->mc_next = *tp; \
8410 *tp = tracked->mc_next; \
8413 /** Move a node from csrc to cdst.
8416 mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft)
8423 unsigned short flags;
8427 /* Mark src and dst as dirty. */
8428 if ((rc = mdb_page_touch(csrc)) ||
8429 (rc = mdb_page_touch(cdst)))
8432 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
8433 key.mv_size = csrc->mc_db->md_pad;
8434 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size);
8436 data.mv_data = NULL;
8440 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]);
8441 mdb_cassert(csrc, !((size_t)srcnode & 1));
8442 srcpg = NODEPGNO(srcnode);
8443 flags = srcnode->mn_flags;
8444 if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
8445 unsigned int snum = csrc->mc_snum;
8447 /* must find the lowest key below src */
8448 rc = mdb_page_search_lowest(csrc);
8451 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
8452 key.mv_size = csrc->mc_db->md_pad;
8453 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
8455 s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
8456 key.mv_size = NODEKSZ(s2);
8457 key.mv_data = NODEKEY(s2);
8459 csrc->mc_snum = snum--;
8460 csrc->mc_top = snum;
8462 key.mv_size = NODEKSZ(srcnode);
8463 key.mv_data = NODEKEY(srcnode);
8465 data.mv_size = NODEDSZ(srcnode);
8466 data.mv_data = NODEDATA(srcnode);
8468 mn.mc_xcursor = NULL;
8469 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) {
8470 unsigned int snum = cdst->mc_snum;
8473 /* must find the lowest key below dst */
8474 mdb_cursor_copy(cdst, &mn);
8475 rc = mdb_page_search_lowest(&mn);
8478 if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
8479 bkey.mv_size = mn.mc_db->md_pad;
8480 bkey.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, bkey.mv_size);
8482 s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
8483 bkey.mv_size = NODEKSZ(s2);
8484 bkey.mv_data = NODEKEY(s2);
8486 mn.mc_snum = snum--;
8489 rc = mdb_update_key(&mn, &bkey);
8494 DPRINTF(("moving %s node %u [%s] on page %"Y"u to node %u on page %"Y"u",
8495 IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch",
8496 csrc->mc_ki[csrc->mc_top],
8498 csrc->mc_pg[csrc->mc_top]->mp_pgno,
8499 cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno));
8501 /* Add the node to the destination page.
8503 rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags);
8504 if (rc != MDB_SUCCESS)
8507 /* Delete the node from the source page.
8509 mdb_node_del(csrc, key.mv_size);
8512 /* Adjust other cursors pointing to mp */
8513 MDB_cursor *m2, *m3;
8514 MDB_dbi dbi = csrc->mc_dbi;
8515 MDB_page *mpd, *mps;
8517 mps = csrc->mc_pg[csrc->mc_top];
8518 /* If we're adding on the left, bump others up */
8520 mpd = cdst->mc_pg[csrc->mc_top];
8521 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8522 if (csrc->mc_flags & C_SUB)
8523 m3 = &m2->mc_xcursor->mx_cursor;
8526 if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
8529 m3->mc_pg[csrc->mc_top] == mpd &&
8530 m3->mc_ki[csrc->mc_top] >= cdst->mc_ki[csrc->mc_top]) {
8531 m3->mc_ki[csrc->mc_top]++;
8534 m3->mc_pg[csrc->mc_top] == mps &&
8535 m3->mc_ki[csrc->mc_top] == csrc->mc_ki[csrc->mc_top]) {
8536 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
8537 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
8538 m3->mc_ki[csrc->mc_top-1]++;
8540 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
8542 MDB_node *node = NODEPTR(m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);
8543 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
8544 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
8548 /* Adding on the right, bump others down */
8550 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8551 if (csrc->mc_flags & C_SUB)
8552 m3 = &m2->mc_xcursor->mx_cursor;
8555 if (m3 == csrc) continue;
8556 if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
8558 if (m3->mc_pg[csrc->mc_top] == mps) {
8559 if (!m3->mc_ki[csrc->mc_top]) {
8560 m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
8561 m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top];
8562 m3->mc_ki[csrc->mc_top-1]--;
8564 m3->mc_ki[csrc->mc_top]--;
8566 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
8568 MDB_node *node = NODEPTR(m3->mc_pg[csrc->mc_top], m3->mc_ki[csrc->mc_top]);
8569 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
8570 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
8577 /* Update the parent separators.
8579 if (csrc->mc_ki[csrc->mc_top] == 0) {
8580 if (csrc->mc_ki[csrc->mc_top-1] != 0) {
8581 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
8582 key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
8584 srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0);
8585 key.mv_size = NODEKSZ(srcnode);
8586 key.mv_data = NODEKEY(srcnode);
8588 DPRINTF(("update separator for source page %"Y"u to [%s]",
8589 csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)));
8590 mdb_cursor_copy(csrc, &mn);
8593 /* We want mdb_rebalance to find mn when doing fixups */
8594 WITH_CURSOR_TRACKING(mn,
8595 rc = mdb_update_key(&mn, &key));
8599 if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
8601 indx_t ix = csrc->mc_ki[csrc->mc_top];
8602 nullkey.mv_size = 0;
8603 csrc->mc_ki[csrc->mc_top] = 0;
8604 rc = mdb_update_key(csrc, &nullkey);
8605 csrc->mc_ki[csrc->mc_top] = ix;
8606 mdb_cassert(csrc, rc == MDB_SUCCESS);
8610 if (cdst->mc_ki[cdst->mc_top] == 0) {
8611 if (cdst->mc_ki[cdst->mc_top-1] != 0) {
8612 if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
8613 key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
8615 srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0);
8616 key.mv_size = NODEKSZ(srcnode);
8617 key.mv_data = NODEKEY(srcnode);
8619 DPRINTF(("update separator for destination page %"Y"u to [%s]",
8620 cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)));
8621 mdb_cursor_copy(cdst, &mn);
8624 /* We want mdb_rebalance to find mn when doing fixups */
8625 WITH_CURSOR_TRACKING(mn,
8626 rc = mdb_update_key(&mn, &key));
8630 if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
8632 indx_t ix = cdst->mc_ki[cdst->mc_top];
8633 nullkey.mv_size = 0;
8634 cdst->mc_ki[cdst->mc_top] = 0;
8635 rc = mdb_update_key(cdst, &nullkey);
8636 cdst->mc_ki[cdst->mc_top] = ix;
8637 mdb_cassert(cdst, rc == MDB_SUCCESS);
8644 /** Merge one page into another.
8645 * The nodes from the page pointed to by \b csrc will
8646 * be copied to the page pointed to by \b cdst and then
8647 * the \b csrc page will be freed.
8648 * @param[in] csrc Cursor pointing to the source page.
8649 * @param[in] cdst Cursor pointing to the destination page.
8650 * @return 0 on success, non-zero on failure.
8653 mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
8655 MDB_page *psrc, *pdst;
8662 psrc = csrc->mc_pg[csrc->mc_top];
8663 pdst = cdst->mc_pg[cdst->mc_top];
8665 DPRINTF(("merging page %"Y"u into %"Y"u", psrc->mp_pgno, pdst->mp_pgno));
8667 mdb_cassert(csrc, csrc->mc_snum > 1); /* can't merge root page */
8668 mdb_cassert(csrc, cdst->mc_snum > 1);
8670 /* Mark dst as dirty. */
8671 if ((rc = mdb_page_touch(cdst)))
8674 /* get dst page again now that we've touched it. */
8675 pdst = cdst->mc_pg[cdst->mc_top];
8677 /* Move all nodes from src to dst.
8679 j = nkeys = NUMKEYS(pdst);
8680 if (IS_LEAF2(psrc)) {
8681 key.mv_size = csrc->mc_db->md_pad;
8682 key.mv_data = METADATA(psrc);
8683 for (i = 0; i < NUMKEYS(psrc); i++, j++) {
8684 rc = mdb_node_add(cdst, j, &key, NULL, 0, 0);
8685 if (rc != MDB_SUCCESS)
8687 key.mv_data = (char *)key.mv_data + key.mv_size;
8690 for (i = 0; i < NUMKEYS(psrc); i++, j++) {
8691 srcnode = NODEPTR(psrc, i);
8692 if (i == 0 && IS_BRANCH(psrc)) {
8695 mdb_cursor_copy(csrc, &mn);
8696 mn.mc_xcursor = NULL;
8697 /* must find the lowest key below src */
8698 rc = mdb_page_search_lowest(&mn);
8701 if (IS_LEAF2(mn.mc_pg[mn.mc_top])) {
8702 key.mv_size = mn.mc_db->md_pad;
8703 key.mv_data = LEAF2KEY(mn.mc_pg[mn.mc_top], 0, key.mv_size);
8705 s2 = NODEPTR(mn.mc_pg[mn.mc_top], 0);
8706 key.mv_size = NODEKSZ(s2);
8707 key.mv_data = NODEKEY(s2);
8710 key.mv_size = srcnode->mn_ksize;
8711 key.mv_data = NODEKEY(srcnode);
8714 data.mv_size = NODEDSZ(srcnode);
8715 data.mv_data = NODEDATA(srcnode);
8716 rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags);
8717 if (rc != MDB_SUCCESS)
8722 DPRINTF(("dst page %"Y"u now has %u keys (%.1f%% filled)",
8723 pdst->mp_pgno, NUMKEYS(pdst),
8724 (float)PAGEFILL(cdst->mc_txn->mt_env, pdst) / 10));
8726 /* Unlink the src page from parent and add to free list.
8729 mdb_node_del(csrc, 0);
8730 if (csrc->mc_ki[csrc->mc_top] == 0) {
8732 rc = mdb_update_key(csrc, &key);
8740 psrc = csrc->mc_pg[csrc->mc_top];
8741 /* If not operating on FreeDB, allow this page to be reused
8742 * in this txn. Otherwise just add to free list.
8744 rc = mdb_page_loose(csrc, psrc);
8748 csrc->mc_db->md_leaf_pages--;
8750 csrc->mc_db->md_branch_pages--;
8752 /* Adjust other cursors pointing to mp */
8753 MDB_cursor *m2, *m3;
8754 MDB_dbi dbi = csrc->mc_dbi;
8755 unsigned int top = csrc->mc_top;
8757 for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8758 if (csrc->mc_flags & C_SUB)
8759 m3 = &m2->mc_xcursor->mx_cursor;
8762 if (m3 == csrc) continue;
8763 if (m3->mc_snum < csrc->mc_snum) continue;
8764 if (m3->mc_pg[top] == psrc) {
8765 m3->mc_pg[top] = pdst;
8766 m3->mc_ki[top] += nkeys;
8767 m3->mc_ki[top-1] = cdst->mc_ki[top-1];
8768 } else if (m3->mc_pg[top-1] == csrc->mc_pg[top-1] &&
8769 m3->mc_ki[top-1] > csrc->mc_ki[top-1]) {
8772 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
8774 MDB_node *node = NODEPTR(m3->mc_pg[top], m3->mc_ki[top]);
8775 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
8776 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
8781 unsigned int snum = cdst->mc_snum;
8782 uint16_t depth = cdst->mc_db->md_depth;
8783 mdb_cursor_pop(cdst);
8784 rc = mdb_rebalance(cdst);
8785 /* Did the tree height change? */
8786 if (depth != cdst->mc_db->md_depth)
8787 snum += cdst->mc_db->md_depth - depth;
8788 cdst->mc_snum = snum;
8789 cdst->mc_top = snum-1;
8794 /** Copy the contents of a cursor.
8795 * @param[in] csrc The cursor to copy from.
8796 * @param[out] cdst The cursor to copy to.
8799 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst)
8803 cdst->mc_txn = csrc->mc_txn;
8804 cdst->mc_dbi = csrc->mc_dbi;
8805 cdst->mc_db = csrc->mc_db;
8806 cdst->mc_dbx = csrc->mc_dbx;
8807 cdst->mc_snum = csrc->mc_snum;
8808 cdst->mc_top = csrc->mc_top;
8809 cdst->mc_flags = csrc->mc_flags;
8810 MC_SET_OVPG(cdst, MC_OVPG(csrc));
8812 for (i=0; i<csrc->mc_snum; i++) {
8813 cdst->mc_pg[i] = csrc->mc_pg[i];
8814 cdst->mc_ki[i] = csrc->mc_ki[i];
8818 /** Rebalance the tree after a delete operation.
8819 * @param[in] mc Cursor pointing to the page where rebalancing
8821 * @return 0 on success, non-zero on failure.
8824 mdb_rebalance(MDB_cursor *mc)
8828 unsigned int ptop, minkeys, thresh;
8832 if (IS_BRANCH(mc->mc_pg[mc->mc_top])) {
8837 thresh = FILL_THRESHOLD;
8839 DPRINTF(("rebalancing %s page %"Y"u (has %u keys, %.1f%% full)",
8840 IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch",
8841 mdb_dbg_pgno(mc->mc_pg[mc->mc_top]), NUMKEYS(mc->mc_pg[mc->mc_top]),
8842 (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10));
8844 if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= thresh &&
8845 NUMKEYS(mc->mc_pg[mc->mc_top]) >= minkeys) {
8846 DPRINTF(("no need to rebalance page %"Y"u, above fill threshold",
8847 mdb_dbg_pgno(mc->mc_pg[mc->mc_top])));
8851 if (mc->mc_snum < 2) {
8852 MDB_page *mp = mc->mc_pg[0];
8854 DPUTS("Can't rebalance a subpage, ignoring");
8857 if (NUMKEYS(mp) == 0) {
8858 DPUTS("tree is completely empty");
8859 mc->mc_db->md_root = P_INVALID;
8860 mc->mc_db->md_depth = 0;
8861 mc->mc_db->md_leaf_pages = 0;
8862 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
8865 /* Adjust cursors pointing to mp */
8868 mc->mc_flags &= ~C_INITIALIZED;
8870 MDB_cursor *m2, *m3;
8871 MDB_dbi dbi = mc->mc_dbi;
8873 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8874 if (mc->mc_flags & C_SUB)
8875 m3 = &m2->mc_xcursor->mx_cursor;
8878 if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum))
8880 if (m3->mc_pg[0] == mp) {
8883 m3->mc_flags &= ~C_INITIALIZED;
8887 } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) {
8889 DPUTS("collapsing root page!");
8890 rc = mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno);
8893 mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0));
8894 rc = mdb_page_get(mc, mc->mc_db->md_root, &mc->mc_pg[0], NULL);
8897 mc->mc_db->md_depth--;
8898 mc->mc_db->md_branch_pages--;
8899 mc->mc_ki[0] = mc->mc_ki[1];
8900 for (i = 1; i<mc->mc_db->md_depth; i++) {
8901 mc->mc_pg[i] = mc->mc_pg[i+1];
8902 mc->mc_ki[i] = mc->mc_ki[i+1];
8905 /* Adjust other cursors pointing to mp */
8906 MDB_cursor *m2, *m3;
8907 MDB_dbi dbi = mc->mc_dbi;
8909 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
8910 if (mc->mc_flags & C_SUB)
8911 m3 = &m2->mc_xcursor->mx_cursor;
8914 if (m3 == mc) continue;
8915 if (!(m3->mc_flags & C_INITIALIZED))
8917 if (m3->mc_pg[0] == mp) {
8918 for (i=0; i<mc->mc_db->md_depth; i++) {
8919 m3->mc_pg[i] = m3->mc_pg[i+1];
8920 m3->mc_ki[i] = m3->mc_ki[i+1];
8928 DPUTS("root page doesn't need rebalancing");
8932 /* The parent (branch page) must have at least 2 pointers,
8933 * otherwise the tree is invalid.
8935 ptop = mc->mc_top-1;
8936 mdb_cassert(mc, NUMKEYS(mc->mc_pg[ptop]) > 1);
8938 /* Leaf page fill factor is below the threshold.
8939 * Try to move keys from left or right neighbor, or
8940 * merge with a neighbor page.
8945 mdb_cursor_copy(mc, &mn);
8946 mn.mc_xcursor = NULL;
8948 oldki = mc->mc_ki[mc->mc_top];
8949 if (mc->mc_ki[ptop] == 0) {
8950 /* We're the leftmost leaf in our parent.
8952 DPUTS("reading right neighbor");
8954 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
8955 rc = mdb_page_get(mc, NODEPGNO(node), &mn.mc_pg[mn.mc_top], NULL);
8958 mn.mc_ki[mn.mc_top] = 0;
8959 mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
8962 /* There is at least one neighbor to the left.
8964 DPUTS("reading left neighbor");
8966 node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]);
8967 rc = mdb_page_get(mc, NODEPGNO(node), &mn.mc_pg[mn.mc_top], NULL);
8970 mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
8971 mc->mc_ki[mc->mc_top] = 0;
8975 DPRINTF(("found neighbor page %"Y"u (%u keys, %.1f%% full)",
8976 mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]),
8977 (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10));
8979 /* If the neighbor page is above threshold and has enough keys,
8980 * move one key from it. Otherwise we should try to merge them.
8981 * (A branch page must never have less than 2 keys.)
8983 if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
8984 rc = mdb_node_move(&mn, mc, fromleft);
8986 /* if we inserted on left, bump position up */
8991 rc = mdb_page_merge(&mn, mc);
8993 oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);
8994 mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
8995 /* We want mdb_rebalance to find mn when doing fixups */
8996 WITH_CURSOR_TRACKING(mn,
8997 rc = mdb_page_merge(mc, &mn));
8998 mdb_cursor_copy(&mn, mc);
9000 mc->mc_flags &= ~C_EOF;
9002 mc->mc_ki[mc->mc_top] = oldki;
9006 /** Complete a delete operation started by #mdb_cursor_del(). */
9008 mdb_cursor_del0(MDB_cursor *mc)
9014 MDB_cursor *m2, *m3;
9015 MDB_dbi dbi = mc->mc_dbi;
9017 ki = mc->mc_ki[mc->mc_top];
9018 mp = mc->mc_pg[mc->mc_top];
9019 mdb_node_del(mc, mc->mc_db->md_pad);
9020 mc->mc_db->md_entries--;
9022 /* Adjust other cursors pointing to mp */
9023 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
9024 m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
9025 if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
9027 if (m3 == mc || m3->mc_snum < mc->mc_snum)
9029 if (m3->mc_pg[mc->mc_top] == mp) {
9030 if (m3->mc_ki[mc->mc_top] == ki) {
9031 m3->mc_flags |= C_DEL;
9032 } else if (m3->mc_ki[mc->mc_top] > ki) {
9033 m3->mc_ki[mc->mc_top]--;
9035 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
9036 MDB_node *node = NODEPTR(m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);
9037 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
9038 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
9043 rc = mdb_rebalance(mc);
9045 if (rc == MDB_SUCCESS) {
9046 /* DB is totally empty now, just bail out.
9047 * Other cursors adjustments were already done
9048 * by mdb_rebalance and aren't needed here.
9053 mp = mc->mc_pg[mc->mc_top];
9054 nkeys = NUMKEYS(mp);
9056 /* Adjust other cursors pointing to mp */
9057 for (m2 = mc->mc_txn->mt_cursors[dbi]; !rc && m2; m2=m2->mc_next) {
9058 m3 = (mc->mc_flags & C_SUB) ? &m2->mc_xcursor->mx_cursor : m2;
9059 if (! (m2->mc_flags & m3->mc_flags & C_INITIALIZED))
9061 if (m3->mc_snum < mc->mc_snum)
9063 if (m3->mc_pg[mc->mc_top] == mp) {
9064 /* if m3 points past last node in page, find next sibling */
9065 if (m3->mc_ki[mc->mc_top] >= mc->mc_ki[mc->mc_top]) {
9066 if (m3->mc_ki[mc->mc_top] >= nkeys) {
9067 rc = mdb_cursor_sibling(m3, 1);
9068 if (rc == MDB_NOTFOUND) {
9069 m3->mc_flags |= C_EOF;
9074 if (mc->mc_db->md_flags & MDB_DUPSORT) {
9075 MDB_node *node = NODEPTR(m3->mc_pg[m3->mc_top], m3->mc_ki[m3->mc_top]);
9076 if (node->mn_flags & F_DUPDATA) {
9077 mdb_xcursor_init1(m3, node);
9078 m3->mc_xcursor->mx_cursor.mc_flags |= C_DEL;
9084 mc->mc_flags |= C_DEL;
9088 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
9093 mdb_del(MDB_txn *txn, MDB_dbi dbi,
9094 MDB_val *key, MDB_val *data)
9096 if (!key || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9099 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
9100 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
9102 if (!F_ISSET(txn->mt_dbs[dbi].md_flags, MDB_DUPSORT)) {
9103 /* must ignore any data */
9107 return mdb_del0(txn, dbi, key, data, 0);
9111 mdb_del0(MDB_txn *txn, MDB_dbi dbi,
9112 MDB_val *key, MDB_val *data, unsigned flags)
9117 MDB_val rdata, *xdata;
9121 DPRINTF(("====> delete db %u key [%s]", dbi, DKEY(key)));
9123 mdb_cursor_init(&mc, txn, dbi, &mx);
9132 flags |= MDB_NODUPDATA;
9134 rc = mdb_cursor_set(&mc, key, xdata, op, &exact);
9136 /* let mdb_page_split know about this cursor if needed:
9137 * delete will trigger a rebalance; if it needs to move
9138 * a node from one page to another, it will have to
9139 * update the parent's separator key(s). If the new sepkey
9140 * is larger than the current one, the parent page may
9141 * run out of space, triggering a split. We need this
9142 * cursor to be consistent until the end of the rebalance.
9144 mc.mc_flags |= C_UNTRACK;
9145 mc.mc_next = txn->mt_cursors[dbi];
9146 txn->mt_cursors[dbi] = &mc;
9147 rc = mdb_cursor_del(&mc, flags);
9148 txn->mt_cursors[dbi] = mc.mc_next;
9153 /** Split a page and insert a new node.
9154 * @param[in,out] mc Cursor pointing to the page and desired insertion index.
9155 * The cursor will be updated to point to the actual page and index where
9156 * the node got inserted after the split.
9157 * @param[in] newkey The key for the newly inserted node.
9158 * @param[in] newdata The data for the newly inserted node.
9159 * @param[in] newpgno The page number, if the new node is a branch node.
9160 * @param[in] nflags The #NODE_ADD_FLAGS for the new node.
9161 * @return 0 on success, non-zero on failure.
9164 mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno,
9165 unsigned int nflags)
9168 int rc = MDB_SUCCESS, new_root = 0, did_split = 0;
9171 int i, j, split_indx, nkeys, pmax;
9172 MDB_env *env = mc->mc_txn->mt_env;
9174 MDB_val sepkey, rkey, xdata, *rdata = &xdata;
9175 MDB_page *copy = NULL;
9176 MDB_page *mp, *rp, *pp;
9181 mp = mc->mc_pg[mc->mc_top];
9182 newindx = mc->mc_ki[mc->mc_top];
9183 nkeys = NUMKEYS(mp);
9185 DPRINTF(("-----> splitting %s page %"Y"u and adding [%s] at index %i/%i",
9186 IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno,
9187 DKEY(newkey), mc->mc_ki[mc->mc_top], nkeys));
9189 /* Create a right sibling. */
9190 if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp)))
9192 rp->mp_pad = mp->mp_pad;
9193 DPRINTF(("new right sibling: page %"Y"u", rp->mp_pgno));
9195 /* Usually when splitting the root page, the cursor
9196 * height is 1. But when called from mdb_update_key,
9197 * the cursor height may be greater because it walks
9198 * up the stack while finding the branch slot to update.
9200 if (mc->mc_top < 1) {
9201 if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
9203 /* shift current top to make room for new parent */
9204 for (i=mc->mc_snum; i>0; i--) {
9205 mc->mc_pg[i] = mc->mc_pg[i-1];
9206 mc->mc_ki[i] = mc->mc_ki[i-1];
9210 mc->mc_db->md_root = pp->mp_pgno;
9211 DPRINTF(("root split! new root = %"Y"u", pp->mp_pgno));
9212 new_root = mc->mc_db->md_depth++;
9214 /* Add left (implicit) pointer. */
9215 if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) {
9216 /* undo the pre-push */
9217 mc->mc_pg[0] = mc->mc_pg[1];
9218 mc->mc_ki[0] = mc->mc_ki[1];
9219 mc->mc_db->md_root = mp->mp_pgno;
9220 mc->mc_db->md_depth--;
9227 ptop = mc->mc_top-1;
9228 DPRINTF(("parent branch page is %"Y"u", mc->mc_pg[ptop]->mp_pgno));
9231 mdb_cursor_copy(mc, &mn);
9232 mn.mc_xcursor = NULL;
9233 mn.mc_pg[mn.mc_top] = rp;
9234 mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
9236 if (nflags & MDB_APPEND) {
9237 mn.mc_ki[mn.mc_top] = 0;
9239 split_indx = newindx;
9243 split_indx = (nkeys+1) / 2;
9248 unsigned int lsize, rsize, ksize;
9249 /* Move half of the keys to the right sibling */
9250 x = mc->mc_ki[mc->mc_top] - split_indx;
9251 ksize = mc->mc_db->md_pad;
9252 split = LEAF2KEY(mp, split_indx, ksize);
9253 rsize = (nkeys - split_indx) * ksize;
9254 lsize = (nkeys - split_indx) * sizeof(indx_t);
9255 mp->mp_lower -= lsize;
9256 rp->mp_lower += lsize;
9257 mp->mp_upper += rsize - lsize;
9258 rp->mp_upper -= rsize - lsize;
9259 sepkey.mv_size = ksize;
9260 if (newindx == split_indx) {
9261 sepkey.mv_data = newkey->mv_data;
9263 sepkey.mv_data = split;
9266 ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize);
9267 memcpy(rp->mp_ptrs, split, rsize);
9268 sepkey.mv_data = rp->mp_ptrs;
9269 memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize);
9270 memcpy(ins, newkey->mv_data, ksize);
9271 mp->mp_lower += sizeof(indx_t);
9272 mp->mp_upper -= ksize - sizeof(indx_t);
9275 memcpy(rp->mp_ptrs, split, x * ksize);
9276 ins = LEAF2KEY(rp, x, ksize);
9277 memcpy(ins, newkey->mv_data, ksize);
9278 memcpy(ins+ksize, split + x * ksize, rsize - x * ksize);
9279 rp->mp_lower += sizeof(indx_t);
9280 rp->mp_upper -= ksize - sizeof(indx_t);
9281 mc->mc_ki[mc->mc_top] = x;
9284 int psize, nsize, k;
9285 /* Maximum free space in an empty page */
9286 pmax = env->me_psize - PAGEHDRSZ;
9288 nsize = mdb_leaf_size(env, newkey, newdata);
9290 nsize = mdb_branch_size(env, newkey);
9291 nsize = EVEN(nsize);
9293 /* grab a page to hold a temporary copy */
9294 copy = mdb_page_malloc(mc->mc_txn, 1);
9299 copy->mp_pgno = mp->mp_pgno;
9300 copy->mp_flags = mp->mp_flags;
9301 copy->mp_lower = (PAGEHDRSZ-PAGEBASE);
9302 copy->mp_upper = env->me_psize - PAGEBASE;
9304 /* prepare to insert */
9305 for (i=0, j=0; i<nkeys; i++) {
9307 copy->mp_ptrs[j++] = 0;
9309 copy->mp_ptrs[j++] = mp->mp_ptrs[i];
9312 /* When items are relatively large the split point needs
9313 * to be checked, because being off-by-one will make the
9314 * difference between success or failure in mdb_node_add.
9316 * It's also relevant if a page happens to be laid out
9317 * such that one half of its nodes are all "small" and
9318 * the other half of its nodes are "large." If the new
9319 * item is also "large" and falls on the half with
9320 * "large" nodes, it also may not fit.
9322 * As a final tweak, if the new item goes on the last
9323 * spot on the page (and thus, onto the new page), bias
9324 * the split so the new page is emptier than the old page.
9325 * This yields better packing during sequential inserts.
9327 if (nkeys < 20 || nsize > pmax/16 || newindx >= nkeys) {
9328 /* Find split point */
9330 if (newindx <= split_indx || newindx >= nkeys) {
9332 k = newindx >= nkeys ? nkeys : split_indx+1+IS_LEAF(mp);
9337 for (; i!=k; i+=j) {
9342 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
9343 psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t);
9345 if (F_ISSET(node->mn_flags, F_BIGDATA))
9346 psize += sizeof(pgno_t);
9348 psize += NODEDSZ(node);
9350 psize = EVEN(psize);
9352 if (psize > pmax || i == k-j) {
9353 split_indx = i + (j<0);
9358 if (split_indx == newindx) {
9359 sepkey.mv_size = newkey->mv_size;
9360 sepkey.mv_data = newkey->mv_data;
9362 node = (MDB_node *)((char *)mp + copy->mp_ptrs[split_indx] + PAGEBASE);
9363 sepkey.mv_size = node->mn_ksize;
9364 sepkey.mv_data = NODEKEY(node);
9369 DPRINTF(("separator is %d [%s]", split_indx, DKEY(&sepkey)));
9371 /* Copy separator key to the parent.
9373 if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
9374 int snum = mc->mc_snum;
9378 /* We want other splits to find mn when doing fixups */
9379 WITH_CURSOR_TRACKING(mn,
9380 rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0));
9385 if (mc->mc_snum > snum) {
9388 /* Right page might now have changed parent.
9389 * Check if left page also changed parent.
9391 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
9392 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
9393 for (i=0; i<ptop; i++) {
9394 mc->mc_pg[i] = mn.mc_pg[i];
9395 mc->mc_ki[i] = mn.mc_ki[i];
9397 mc->mc_pg[ptop] = mn.mc_pg[ptop];
9398 if (mn.mc_ki[ptop]) {
9399 mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1;
9401 /* find right page's left sibling */
9402 mc->mc_ki[ptop] = mn.mc_ki[ptop];
9403 mdb_cursor_sibling(mc, 0);
9408 rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
9411 if (rc != MDB_SUCCESS) {
9414 if (nflags & MDB_APPEND) {
9415 mc->mc_pg[mc->mc_top] = rp;
9416 mc->mc_ki[mc->mc_top] = 0;
9417 rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags);
9420 for (i=0; i<mc->mc_top; i++)
9421 mc->mc_ki[i] = mn.mc_ki[i];
9422 } else if (!IS_LEAF2(mp)) {
9424 mc->mc_pg[mc->mc_top] = rp;
9429 rkey.mv_data = newkey->mv_data;
9430 rkey.mv_size = newkey->mv_size;
9436 /* Update index for the new key. */
9437 mc->mc_ki[mc->mc_top] = j;
9439 node = (MDB_node *)((char *)mp + copy->mp_ptrs[i] + PAGEBASE);
9440 rkey.mv_data = NODEKEY(node);
9441 rkey.mv_size = node->mn_ksize;
9443 xdata.mv_data = NODEDATA(node);
9444 xdata.mv_size = NODEDSZ(node);
9447 pgno = NODEPGNO(node);
9448 flags = node->mn_flags;
9451 if (!IS_LEAF(mp) && j == 0) {
9452 /* First branch index doesn't need key data. */
9456 rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags);
9462 mc->mc_pg[mc->mc_top] = copy;
9467 } while (i != split_indx);
9469 nkeys = NUMKEYS(copy);
9470 for (i=0; i<nkeys; i++)
9471 mp->mp_ptrs[i] = copy->mp_ptrs[i];
9472 mp->mp_lower = copy->mp_lower;
9473 mp->mp_upper = copy->mp_upper;
9474 memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1),
9475 env->me_psize - copy->mp_upper - PAGEBASE);
9477 /* reset back to original page */
9478 if (newindx < split_indx) {
9479 mc->mc_pg[mc->mc_top] = mp;
9481 mc->mc_pg[mc->mc_top] = rp;
9483 /* Make sure mc_ki is still valid.
9485 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
9486 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
9487 for (i=0; i<=ptop; i++) {
9488 mc->mc_pg[i] = mn.mc_pg[i];
9489 mc->mc_ki[i] = mn.mc_ki[i];
9493 if (nflags & MDB_RESERVE) {
9494 node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
9495 if (!(node->mn_flags & F_BIGDATA))
9496 newdata->mv_data = NODEDATA(node);
9499 if (newindx >= split_indx) {
9500 mc->mc_pg[mc->mc_top] = rp;
9502 /* Make sure mc_ki is still valid.
9504 if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
9505 mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
9506 for (i=0; i<=ptop; i++) {
9507 mc->mc_pg[i] = mn.mc_pg[i];
9508 mc->mc_ki[i] = mn.mc_ki[i];
9515 /* Adjust other cursors pointing to mp */
9516 MDB_cursor *m2, *m3;
9517 MDB_dbi dbi = mc->mc_dbi;
9518 nkeys = NUMKEYS(mp);
9520 for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
9521 if (mc->mc_flags & C_SUB)
9522 m3 = &m2->mc_xcursor->mx_cursor;
9527 if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
9531 /* sub cursors may be on different DB */
9532 if (m3->mc_pg[0] != mp)
9535 for (k=new_root; k>=0; k--) {
9536 m3->mc_ki[k+1] = m3->mc_ki[k];
9537 m3->mc_pg[k+1] = m3->mc_pg[k];
9539 if (m3->mc_ki[0] >= nkeys) {
9544 m3->mc_pg[0] = mc->mc_pg[0];
9548 if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
9549 if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
9550 m3->mc_ki[mc->mc_top]++;
9551 if (m3->mc_ki[mc->mc_top] >= nkeys) {
9552 m3->mc_pg[mc->mc_top] = rp;
9553 m3->mc_ki[mc->mc_top] -= nkeys;
9554 for (i=0; i<mc->mc_top; i++) {
9555 m3->mc_ki[i] = mn.mc_ki[i];
9556 m3->mc_pg[i] = mn.mc_pg[i];
9559 } else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
9560 m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
9563 if (m3->mc_xcursor && (m3->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) &&
9565 MDB_node *node = NODEPTR(m3->mc_pg[mc->mc_top], m3->mc_ki[mc->mc_top]);
9566 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA)
9567 m3->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(node);
9571 DPRINTF(("mp left: %d, rp left: %d", SIZELEFT(mp), SIZELEFT(rp)));
9574 if (copy) /* tmp page */
9575 mdb_page_free(env, copy);
9577 mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
9582 mdb_put(MDB_txn *txn, MDB_dbi dbi,
9583 MDB_val *key, MDB_val *data, unsigned int flags)
9589 if (!key || !data || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
9592 if (flags & ~(MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND|MDB_APPENDDUP))
9595 if (txn->mt_flags & (MDB_TXN_RDONLY|MDB_TXN_BLOCKED))
9596 return (txn->mt_flags & MDB_TXN_RDONLY) ? EACCES : MDB_BAD_TXN;
9598 mdb_cursor_init(&mc, txn, dbi, &mx);
9599 mc.mc_next = txn->mt_cursors[dbi];
9600 txn->mt_cursors[dbi] = &mc;
9601 rc = mdb_cursor_put(&mc, key, data, flags);
9602 txn->mt_cursors[dbi] = mc.mc_next;
9607 #define MDB_WBUF (1024*1024)
9609 #define MDB_EOF 0x10 /**< #mdb_env_copyfd1() is done reading */
9611 /** State needed for a double-buffering compacting copy. */
9612 typedef struct mdb_copy {
9613 pthread_mutex_t mc_mutex;
9614 pthread_cond_t mc_cond; /**< Condition variable for #mc_new */
9621 pgno_t mc_next_pgno;
9623 int mc_toggle; /**< Buffer number in provider */
9624 int mc_new; /**< (0-2 buffers to write) | (#MDB_EOF at end) */
9625 volatile int mc_error; /**< Error code, never cleared if set */
9628 /** Dedicated writer thread for compacting copy. */
9629 static THREAD_RET ESECT CALL_CONV
9630 mdb_env_copythr(void *arg)
9634 int toggle = 0, wsize, rc;
9637 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
9640 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
9643 pthread_mutex_lock(&my->mc_mutex);
9646 pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
9647 if (my->mc_new == 0 + MDB_EOF) /* 0 buffers, just EOF */
9649 wsize = my->mc_wlen[toggle];
9650 ptr = my->mc_wbuf[toggle];
9653 while (wsize > 0 && !my->mc_error) {
9654 DO_WRITE(rc, my->mc_fd, ptr, wsize, len);
9658 } else if (len > 0) {
9671 /* If there's an overflow page tail, write it too */
9672 if (my->mc_olen[toggle]) {
9673 wsize = my->mc_olen[toggle];
9674 ptr = my->mc_over[toggle];
9675 my->mc_olen[toggle] = 0;
9678 my->mc_wlen[toggle] = 0;
9680 /* Return the empty buffer to provider */
9682 pthread_cond_signal(&my->mc_cond);
9684 pthread_mutex_unlock(&my->mc_mutex);
9685 return (THREAD_RET)0;
9689 /** Give buffer and/or #MDB_EOF to writer thread, await unused buffer.
9691 * @param[in] my control structure.
9692 * @param[in] adjust (1 to hand off 1 buffer) | (MDB_EOF when ending).
9695 mdb_env_cthr_toggle(mdb_copy *my, int adjust)
9697 pthread_mutex_lock(&my->mc_mutex);
9698 my->mc_new += adjust;
9699 pthread_cond_signal(&my->mc_cond);
9700 while (my->mc_new & 2) /* both buffers in use */
9701 pthread_cond_wait(&my->mc_cond, &my->mc_mutex);
9702 pthread_mutex_unlock(&my->mc_mutex);
9704 my->mc_toggle ^= (adjust & 1);
9705 /* Both threads reset mc_wlen, to be safe from threading errors */
9706 my->mc_wlen[my->mc_toggle] = 0;
9707 return my->mc_error;
9710 /** Depth-first tree traversal for compacting copy. */
9712 mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
9714 MDB_cursor mc = {0};
9716 MDB_page *mo, *mp, *leaf;
9721 /* Empty DB, nothing to do */
9722 if (*pg == P_INVALID)
9726 mc.mc_txn = my->mc_txn;
9727 mc.mc_flags = my->mc_txn->mt_flags & (C_ORIG_RDONLY|C_WRITEMAP);
9729 rc = mdb_page_get(&mc, *pg, &mc.mc_pg[0], NULL);
9732 rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST);
9736 /* Make cursor pages writable */
9737 buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum);
9741 for (i=0; i<mc.mc_top; i++) {
9742 mdb_page_copy((MDB_page *)ptr, mc.mc_pg[i], my->mc_env->me_psize);
9743 mc.mc_pg[i] = (MDB_page *)ptr;
9744 ptr += my->mc_env->me_psize;
9747 /* This is writable space for a leaf page. Usually not needed. */
9748 leaf = (MDB_page *)ptr;
9750 toggle = my->mc_toggle;
9751 while (mc.mc_snum > 0) {
9753 mp = mc.mc_pg[mc.mc_top];
9757 if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) {
9758 for (i=0; i<n; i++) {
9759 ni = NODEPTR(mp, i);
9760 if (ni->mn_flags & F_BIGDATA) {
9764 /* Need writable leaf */
9766 mc.mc_pg[mc.mc_top] = leaf;
9767 mdb_page_copy(leaf, mp, my->mc_env->me_psize);
9769 ni = NODEPTR(mp, i);
9772 memcpy(&pg, NODEDATA(ni), sizeof(pg));
9773 memcpy(NODEDATA(ni), &my->mc_next_pgno, sizeof(pgno_t));
9774 rc = mdb_page_get(&mc, pg, &omp, NULL);
9777 if (my->mc_wlen[toggle] >= MDB_WBUF) {
9778 rc = mdb_env_cthr_toggle(my, 1);
9781 toggle = my->mc_toggle;
9783 mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
9784 memcpy(mo, omp, my->mc_env->me_psize);
9785 mo->mp_pgno = my->mc_next_pgno;
9786 my->mc_next_pgno += omp->mp_pages;
9787 my->mc_wlen[toggle] += my->mc_env->me_psize;
9788 if (omp->mp_pages > 1) {
9789 my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1);
9790 my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize;
9791 rc = mdb_env_cthr_toggle(my, 1);
9794 toggle = my->mc_toggle;
9796 } else if (ni->mn_flags & F_SUBDATA) {
9799 /* Need writable leaf */
9801 mc.mc_pg[mc.mc_top] = leaf;
9802 mdb_page_copy(leaf, mp, my->mc_env->me_psize);
9804 ni = NODEPTR(mp, i);
9807 memcpy(&db, NODEDATA(ni), sizeof(db));
9808 my->mc_toggle = toggle;
9809 rc = mdb_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA);
9812 toggle = my->mc_toggle;
9813 memcpy(NODEDATA(ni), &db, sizeof(db));
9818 mc.mc_ki[mc.mc_top]++;
9819 if (mc.mc_ki[mc.mc_top] < n) {
9822 ni = NODEPTR(mp, mc.mc_ki[mc.mc_top]);
9824 rc = mdb_page_get(&mc, pg, &mp, NULL);
9829 mc.mc_ki[mc.mc_top] = 0;
9830 if (IS_BRANCH(mp)) {
9831 /* Whenever we advance to a sibling branch page,
9832 * we must proceed all the way down to its first leaf.
9834 mdb_page_copy(mc.mc_pg[mc.mc_top], mp, my->mc_env->me_psize);
9837 mc.mc_pg[mc.mc_top] = mp;
9841 if (my->mc_wlen[toggle] >= MDB_WBUF) {
9842 rc = mdb_env_cthr_toggle(my, 1);
9845 toggle = my->mc_toggle;
9847 mo = (MDB_page *)(my->mc_wbuf[toggle] + my->mc_wlen[toggle]);
9848 mdb_page_copy(mo, mp, my->mc_env->me_psize);
9849 mo->mp_pgno = my->mc_next_pgno++;
9850 my->mc_wlen[toggle] += my->mc_env->me_psize;
9852 /* Update parent if there is one */
9853 ni = NODEPTR(mc.mc_pg[mc.mc_top-1], mc.mc_ki[mc.mc_top-1]);
9854 SETPGNO(ni, mo->mp_pgno);
9855 mdb_cursor_pop(&mc);
9857 /* Otherwise we're done */
9867 /** Copy environment with compaction. */
9869 mdb_env_copyfd1(MDB_env *env, HANDLE fd)
9874 MDB_txn *txn = NULL;
9876 pgno_t root, new_root;
9877 int rc = MDB_SUCCESS;
9880 if (!(my.mc_mutex = CreateMutex(NULL, FALSE, NULL)) ||
9881 !(my.mc_cond = CreateEvent(NULL, FALSE, FALSE, NULL))) {
9885 my.mc_wbuf[0] = _aligned_malloc(MDB_WBUF*2, env->me_os_psize);
9886 if (my.mc_wbuf[0] == NULL) {
9887 /* _aligned_malloc() sets errno, but we use Windows error codes */
9888 rc = ERROR_NOT_ENOUGH_MEMORY;
9892 if ((rc = pthread_mutex_init(&my.mc_mutex, NULL)) != 0)
9894 if ((rc = pthread_cond_init(&my.mc_cond, NULL)) != 0)
9896 #ifdef HAVE_MEMALIGN
9897 my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF*2);
9898 if (my.mc_wbuf[0] == NULL) {
9905 if ((rc = posix_memalign(&p, env->me_os_psize, MDB_WBUF*2)) != 0)
9911 memset(my.mc_wbuf[0], 0, MDB_WBUF*2);
9912 my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF;
9913 my.mc_next_pgno = NUM_METAS;
9916 rc = THREAD_CREATE(thr, mdb_env_copythr, &my);
9920 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
9924 mp = (MDB_page *)my.mc_wbuf[0];
9925 memset(mp, 0, NUM_METAS * env->me_psize);
9927 mp->mp_flags = P_META;
9928 mm = (MDB_meta *)METADATA(mp);
9929 mdb_env_init_meta0(env, mm);
9930 mm->mm_address = env->me_metas[0]->mm_address;
9932 mp = (MDB_page *)(my.mc_wbuf[0] + env->me_psize);
9934 mp->mp_flags = P_META;
9935 *(MDB_meta *)METADATA(mp) = *mm;
9936 mm = (MDB_meta *)METADATA(mp);
9938 /* Set metapage 1 with current main DB */
9939 root = new_root = txn->mt_dbs[MAIN_DBI].md_root;
9940 if (root != P_INVALID) {
9941 /* Count free pages + freeDB pages. Subtract from last_pg
9942 * to find the new last_pg, which also becomes the new root.
9944 MDB_ID freecount = 0;
9947 mdb_cursor_init(&mc, txn, FREE_DBI, NULL);
9948 while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0)
9949 freecount += *(MDB_ID *)data.mv_data;
9950 if (rc != MDB_NOTFOUND)
9952 freecount += txn->mt_dbs[FREE_DBI].md_branch_pages +
9953 txn->mt_dbs[FREE_DBI].md_leaf_pages +
9954 txn->mt_dbs[FREE_DBI].md_overflow_pages;
9956 new_root = txn->mt_next_pgno - 1 - freecount;
9957 mm->mm_last_pg = new_root;
9958 mm->mm_dbs[MAIN_DBI] = txn->mt_dbs[MAIN_DBI];
9959 mm->mm_dbs[MAIN_DBI].md_root = new_root;
9961 /* When the DB is empty, handle it specially to
9962 * fix any breakage like page leaks from ITS#8174.
9964 mm->mm_dbs[MAIN_DBI].md_flags = txn->mt_dbs[MAIN_DBI].md_flags;
9966 if (root != P_INVALID || mm->mm_dbs[MAIN_DBI].md_flags) {
9967 mm->mm_txnid = 1; /* use metapage 1 */
9970 my.mc_wlen[0] = env->me_psize * NUM_METAS;
9972 rc = mdb_env_cwalk(&my, &root, 0);
9973 if (rc == MDB_SUCCESS && root != new_root) {
9974 rc = MDB_INCOMPATIBLE; /* page leak or corrupt DB */
9980 mdb_env_cthr_toggle(&my, 1 | MDB_EOF);
9981 rc = THREAD_FINISH(thr);
9986 if (my.mc_wbuf[0]) _aligned_free(my.mc_wbuf[0]);
9987 if (my.mc_cond) CloseHandle(my.mc_cond);
9988 if (my.mc_mutex) CloseHandle(my.mc_mutex);
9990 free(my.mc_wbuf[0]);
9991 pthread_cond_destroy(&my.mc_cond);
9993 pthread_mutex_destroy(&my.mc_mutex);
9995 return rc ? rc : my.mc_error;
9998 /** Copy environment as-is. */
10000 mdb_env_copyfd0(MDB_env *env, HANDLE fd)
10002 MDB_txn *txn = NULL;
10003 mdb_mutexref_t wmutex = NULL;
10005 mdb_size_t wsize, w3;
10009 #define DO_WRITE(rc, fd, ptr, w2, len) rc = WriteFile(fd, ptr, w2, &len, NULL)
10013 #define DO_WRITE(rc, fd, ptr, w2, len) len = write(fd, ptr, w2); rc = (len >= 0)
10016 /* Do the lock/unlock of the reader mutex before starting the
10017 * write txn. Otherwise other read txns could block writers.
10019 rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
10023 if (env->me_txns) {
10024 /* We must start the actual read txn after blocking writers */
10025 mdb_txn_end(txn, MDB_END_RESET_TMP);
10027 /* Temporarily block writers until we snapshot the meta pages */
10028 wmutex = env->me_wmutex;
10029 if (LOCK_MUTEX(rc, env, wmutex))
10032 rc = mdb_txn_renew0(txn);
10034 UNLOCK_MUTEX(wmutex);
10039 wsize = env->me_psize * NUM_METAS;
10043 DO_WRITE(rc, fd, ptr, w2, len);
10047 } else if (len > 0) {
10053 /* Non-blocking or async handles are not supported */
10059 UNLOCK_MUTEX(wmutex);
10064 w3 = txn->mt_next_pgno * env->me_psize;
10066 mdb_size_t fsize = 0;
10067 if ((rc = mdb_fsize(env->me_fd, &fsize)))
10072 wsize = w3 - wsize;
10073 while (wsize > 0) {
10074 if (wsize > MAX_WRITE)
10078 DO_WRITE(rc, fd, ptr, w2, len);
10082 } else if (len > 0) {
10094 mdb_txn_abort(txn);
10099 mdb_env_copyfd2(MDB_env *env, HANDLE fd, unsigned int flags)
10101 if (flags & MDB_CP_COMPACT)
10102 return mdb_env_copyfd1(env, fd);
10104 return mdb_env_copyfd0(env, fd);
10108 mdb_env_copyfd(MDB_env *env, HANDLE fd)
10110 return mdb_env_copyfd2(env, fd, 0);
10114 mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)
10118 HANDLE newfd = INVALID_HANDLE_VALUE;
10123 if (env->me_flags & MDB_NOSUBDIR) {
10124 lpath = (char *)path;
10126 len = strlen(path);
10127 len += sizeof(DATANAME);
10128 lpath = malloc(len);
10131 sprintf(lpath, "%s" DATANAME, path);
10134 /* The destination path must exist, but the destination file must not.
10135 * We don't want the OS to cache the writes, since the source data is
10136 * already in the OS cache.
10139 rc = utf8_to_utf16(lpath, -1, &wpath, NULL);
10142 newfd = CreateFileW(wpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
10143 FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
10146 newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL, 0666);
10148 if (newfd == INVALID_HANDLE_VALUE) {
10153 if (env->me_psize >= env->me_os_psize) {
10155 /* Set O_DIRECT if the file system supports it */
10156 if ((rc = fcntl(newfd, F_GETFL)) != -1)
10157 (void) fcntl(newfd, F_SETFL, rc | O_DIRECT);
10159 #ifdef F_NOCACHE /* __APPLE__ */
10160 rc = fcntl(newfd, F_NOCACHE, 1);
10168 rc = mdb_env_copyfd2(env, newfd, flags);
10171 if (!(env->me_flags & MDB_NOSUBDIR))
10173 if (newfd != INVALID_HANDLE_VALUE)
10174 if (close(newfd) < 0 && rc == MDB_SUCCESS)
10181 mdb_env_copy(MDB_env *env, const char *path)
10183 return mdb_env_copy2(env, path, 0);
10187 mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff)
10189 if (flag & ~CHANGEABLE)
10192 env->me_flags |= flag;
10194 env->me_flags &= ~flag;
10195 return MDB_SUCCESS;
10199 mdb_env_get_flags(MDB_env *env, unsigned int *arg)
10204 *arg = env->me_flags & (CHANGEABLE|CHANGELESS);
10205 return MDB_SUCCESS;
10209 mdb_env_set_userctx(MDB_env *env, void *ctx)
10213 env->me_userctx = ctx;
10214 return MDB_SUCCESS;
10218 mdb_env_get_userctx(MDB_env *env)
10220 return env ? env->me_userctx : NULL;
10224 mdb_env_set_assert(MDB_env *env, MDB_assert_func *func)
10229 env->me_assert_func = func;
10231 return MDB_SUCCESS;
10235 mdb_env_get_path(MDB_env *env, const char **arg)
10240 *arg = env->me_path;
10241 return MDB_SUCCESS;
10245 mdb_env_get_fd(MDB_env *env, mdb_filehandle_t *arg)
10251 return MDB_SUCCESS;
10254 /** Common code for #mdb_stat() and #mdb_env_stat().
10255 * @param[in] env the environment to operate in.
10256 * @param[in] db the #MDB_db record containing the stats to return.
10257 * @param[out] arg the address of an #MDB_stat structure to receive the stats.
10258 * @return 0, this function always succeeds.
10261 mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
10263 arg->ms_psize = env->me_psize;
10264 arg->ms_depth = db->md_depth;
10265 arg->ms_branch_pages = db->md_branch_pages;
10266 arg->ms_leaf_pages = db->md_leaf_pages;
10267 arg->ms_overflow_pages = db->md_overflow_pages;
10268 arg->ms_entries = db->md_entries;
10270 return MDB_SUCCESS;
10274 mdb_env_stat(MDB_env *env, MDB_stat *arg)
10278 if (env == NULL || arg == NULL)
10281 meta = mdb_env_pick_meta(env);
10283 return mdb_stat0(env, &meta->mm_dbs[MAIN_DBI], arg);
10287 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
10291 if (env == NULL || arg == NULL)
10294 meta = mdb_env_pick_meta(env);
10295 arg->me_mapaddr = meta->mm_address;
10296 arg->me_last_pgno = meta->mm_last_pg;
10297 arg->me_last_txnid = meta->mm_txnid;
10299 arg->me_mapsize = env->me_mapsize;
10300 arg->me_maxreaders = env->me_maxreaders;
10301 arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : 0;
10302 return MDB_SUCCESS;
10305 /** Set the default comparison functions for a database.
10306 * Called immediately after a database is opened to set the defaults.
10307 * The user can then override them with #mdb_set_compare() or
10308 * #mdb_set_dupsort().
10309 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
10310 * @param[in] dbi A database handle returned by #mdb_dbi_open()
10313 mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi)
10315 uint16_t f = txn->mt_dbs[dbi].md_flags;
10317 txn->mt_dbxs[dbi].md_cmp =
10318 (f & MDB_REVERSEKEY) ? mdb_cmp_memnr :
10319 (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn;
10321 txn->mt_dbxs[dbi].md_dcmp =
10322 !(f & MDB_DUPSORT) ? 0 :
10323 ((f & MDB_INTEGERDUP)
10324 ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint)
10325 : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn));
10328 int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
10334 int rc, dbflag, exact;
10335 unsigned int unused = 0, seq;
10339 if (flags & ~VALID_FLAGS)
10341 if (txn->mt_flags & MDB_TXN_BLOCKED)
10342 return MDB_BAD_TXN;
10347 if (flags & PERSISTENT_FLAGS) {
10348 uint16_t f2 = flags & PERSISTENT_FLAGS;
10349 /* make sure flag changes get committed */
10350 if ((txn->mt_dbs[MAIN_DBI].md_flags | f2) != txn->mt_dbs[MAIN_DBI].md_flags) {
10351 txn->mt_dbs[MAIN_DBI].md_flags |= f2;
10352 txn->mt_flags |= MDB_TXN_DIRTY;
10355 mdb_default_cmp(txn, MAIN_DBI);
10356 return MDB_SUCCESS;
10359 if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
10360 mdb_default_cmp(txn, MAIN_DBI);
10363 /* Is the DB already open? */
10364 len = strlen(name);
10365 for (i=CORE_DBS; i<txn->mt_numdbs; i++) {
10366 if (!txn->mt_dbxs[i].md_name.mv_size) {
10367 /* Remember this free slot */
10368 if (!unused) unused = i;
10371 if (len == txn->mt_dbxs[i].md_name.mv_size &&
10372 !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) {
10374 return MDB_SUCCESS;
10378 /* If no free slot and max hit, fail */
10379 if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
10380 return MDB_DBS_FULL;
10382 /* Cannot mix named databases with some mainDB flags */
10383 if (txn->mt_dbs[MAIN_DBI].md_flags & (MDB_DUPSORT|MDB_INTEGERKEY))
10384 return (flags & MDB_CREATE) ? MDB_INCOMPATIBLE : MDB_NOTFOUND;
10386 /* Find the DB info */
10387 dbflag = DB_NEW|DB_VALID|DB_USRVALID;
10390 key.mv_data = (void *)name;
10391 mdb_cursor_init(&mc, txn, MAIN_DBI, NULL);
10392 rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact);
10393 if (rc == MDB_SUCCESS) {
10394 /* make sure this is actually a DB */
10395 MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
10396 if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
10397 return MDB_INCOMPATIBLE;
10398 } else if (! (rc == MDB_NOTFOUND && (flags & MDB_CREATE))) {
10402 /* Done here so we cannot fail after creating a new DB */
10403 if ((namedup = strdup(name)) == NULL)
10407 /* MDB_NOTFOUND and MDB_CREATE: Create new DB */
10408 data.mv_size = sizeof(MDB_db);
10409 data.mv_data = &dummy;
10410 memset(&dummy, 0, sizeof(dummy));
10411 dummy.md_root = P_INVALID;
10412 dummy.md_flags = flags & PERSISTENT_FLAGS;
10413 rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA);
10414 dbflag |= DB_DIRTY;
10420 /* Got info, register DBI in this txn */
10421 unsigned int slot = unused ? unused : txn->mt_numdbs;
10422 txn->mt_dbxs[slot].md_name.mv_data = namedup;
10423 txn->mt_dbxs[slot].md_name.mv_size = len;
10424 txn->mt_dbxs[slot].md_rel = NULL;
10425 txn->mt_dbflags[slot] = dbflag;
10426 /* txn-> and env-> are the same in read txns, use
10427 * tmp variable to avoid undefined assignment
10429 seq = ++txn->mt_env->me_dbiseqs[slot];
10430 txn->mt_dbiseqs[slot] = seq;
10432 memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db));
10434 mdb_default_cmp(txn, slot);
10444 mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg)
10446 if (!arg || !TXN_DBI_EXIST(txn, dbi, DB_VALID))
10449 if (txn->mt_flags & MDB_TXN_BLOCKED)
10450 return MDB_BAD_TXN;
10452 if (txn->mt_dbflags[dbi] & DB_STALE) {
10455 /* Stale, must read the DB's root. cursor_init does it for us. */
10456 mdb_cursor_init(&mc, txn, dbi, &mx);
10458 return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg);
10461 void mdb_dbi_close(MDB_env *env, MDB_dbi dbi)
10464 if (dbi < CORE_DBS || dbi >= env->me_maxdbs)
10466 ptr = env->me_dbxs[dbi].md_name.mv_data;
10467 /* If there was no name, this was already closed */
10469 env->me_dbxs[dbi].md_name.mv_data = NULL;
10470 env->me_dbxs[dbi].md_name.mv_size = 0;
10471 env->me_dbflags[dbi] = 0;
10472 env->me_dbiseqs[dbi]++;
10477 int mdb_dbi_flags(MDB_txn *txn, MDB_dbi dbi, unsigned int *flags)
10479 /* We could return the flags for the FREE_DBI too but what's the point? */
10480 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
10482 *flags = txn->mt_dbs[dbi].md_flags & PERSISTENT_FLAGS;
10483 return MDB_SUCCESS;
10486 /** Add all the DB's pages to the free list.
10487 * @param[in] mc Cursor on the DB to free.
10488 * @param[in] subs non-Zero to check for sub-DBs in this DB.
10489 * @return 0 on success, non-zero on failure.
10492 mdb_drop0(MDB_cursor *mc, int subs)
10496 rc = mdb_page_search(mc, NULL, MDB_PS_FIRST);
10497 if (rc == MDB_SUCCESS) {
10498 MDB_txn *txn = mc->mc_txn;
10503 /* DUPSORT sub-DBs have no ovpages/DBs. Omit scanning leaves.
10504 * This also avoids any P_LEAF2 pages, which have no nodes.
10505 * Also if the DB doesn't have sub-DBs and has no overflow
10506 * pages, omit scanning leaves.
10508 if ((mc->mc_flags & C_SUB) ||
10509 (!subs && !mc->mc_db->md_overflow_pages))
10510 mdb_cursor_pop(mc);
10512 mdb_cursor_copy(mc, &mx);
10514 /* bump refcount for mx's pages */
10515 for (i=0; i<mc->mc_snum; i++)
10516 mdb_page_get(&mx, mc->mc_pg[i]->mp_pgno, &mx.mc_pg[i], NULL);
10518 while (mc->mc_snum > 0) {
10519 MDB_page *mp = mc->mc_pg[mc->mc_top];
10520 unsigned n = NUMKEYS(mp);
10522 for (i=0; i<n; i++) {
10523 ni = NODEPTR(mp, i);
10524 if (ni->mn_flags & F_BIGDATA) {
10527 memcpy(&pg, NODEDATA(ni), sizeof(pg));
10528 rc = mdb_page_get(mc, pg, &omp, NULL);
10531 mdb_cassert(mc, IS_OVERFLOW(omp));
10532 rc = mdb_midl_append_range(&txn->mt_free_pgs,
10533 pg, omp->mp_pages);
10536 mc->mc_db->md_overflow_pages -= omp->mp_pages;
10537 if (!mc->mc_db->md_overflow_pages && !subs)
10539 } else if (subs && (ni->mn_flags & F_SUBDATA)) {
10540 mdb_xcursor_init1(mc, ni);
10541 rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0);
10546 if (!subs && !mc->mc_db->md_overflow_pages)
10549 if ((rc = mdb_midl_need(&txn->mt_free_pgs, n)) != 0)
10551 for (i=0; i<n; i++) {
10553 ni = NODEPTR(mp, i);
10556 mdb_midl_xappend(txn->mt_free_pgs, pg);
10561 mc->mc_ki[mc->mc_top] = i;
10562 rc = mdb_cursor_sibling(mc, 1);
10564 if (rc != MDB_NOTFOUND)
10566 /* no more siblings, go back to beginning
10567 * of previous level.
10570 mdb_cursor_pop(mc);
10572 for (i=1; i<mc->mc_snum; i++) {
10574 mc->mc_pg[i] = mx.mc_pg[i];
10579 rc = mdb_midl_append(&txn->mt_free_pgs, mc->mc_db->md_root);
10582 txn->mt_flags |= MDB_TXN_ERROR;
10583 /* drop refcount for mx's pages */
10584 MDB_CURSOR_UNREF(&mx, 0);
10585 } else if (rc == MDB_NOTFOUND) {
10588 mc->mc_flags &= ~C_INITIALIZED;
10592 int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
10594 MDB_cursor *mc, *m2;
10597 if ((unsigned)del > 1 || !TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
10600 if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY))
10603 if (TXN_DBI_CHANGED(txn, dbi))
10604 return MDB_BAD_DBI;
10606 rc = mdb_cursor_open(txn, dbi, &mc);
10610 rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT);
10611 /* Invalidate the dropped DB's cursors */
10612 for (m2 = txn->mt_cursors[dbi]; m2; m2 = m2->mc_next)
10613 m2->mc_flags &= ~(C_INITIALIZED|C_EOF);
10617 /* Can't delete the main DB */
10618 if (del && dbi >= CORE_DBS) {
10619 rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, F_SUBDATA);
10621 txn->mt_dbflags[dbi] = DB_STALE;
10622 mdb_dbi_close(txn->mt_env, dbi);
10624 txn->mt_flags |= MDB_TXN_ERROR;
10627 /* reset the DB record, mark it dirty */
10628 txn->mt_dbflags[dbi] |= DB_DIRTY;
10629 txn->mt_dbs[dbi].md_depth = 0;
10630 txn->mt_dbs[dbi].md_branch_pages = 0;
10631 txn->mt_dbs[dbi].md_leaf_pages = 0;
10632 txn->mt_dbs[dbi].md_overflow_pages = 0;
10633 txn->mt_dbs[dbi].md_entries = 0;
10634 txn->mt_dbs[dbi].md_root = P_INVALID;
10636 txn->mt_flags |= MDB_TXN_DIRTY;
10639 mdb_cursor_close(mc);
10643 int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
10645 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
10648 txn->mt_dbxs[dbi].md_cmp = cmp;
10649 return MDB_SUCCESS;
10652 int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp)
10654 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
10657 txn->mt_dbxs[dbi].md_dcmp = cmp;
10658 return MDB_SUCCESS;
10661 int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel)
10663 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
10666 txn->mt_dbxs[dbi].md_rel = rel;
10667 return MDB_SUCCESS;
10670 int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx)
10672 if (!TXN_DBI_EXIST(txn, dbi, DB_USRVALID))
10675 txn->mt_dbxs[dbi].md_relctx = ctx;
10676 return MDB_SUCCESS;
10680 mdb_env_get_maxkeysize(MDB_env *env)
10682 return ENV_MAXKEY(env);
10686 mdb_reader_list(MDB_env *env, MDB_msg_func *func, void *ctx)
10688 unsigned int i, rdrs;
10691 int rc = 0, first = 1;
10695 if (!env->me_txns) {
10696 return func("(no reader locks)\n", ctx);
10698 rdrs = env->me_txns->mti_numreaders;
10699 mr = env->me_txns->mti_readers;
10700 for (i=0; i<rdrs; i++) {
10701 if (mr[i].mr_pid) {
10702 txnid_t txnid = mr[i].mr_txnid;
10703 sprintf(buf, txnid == (txnid_t)-1 ?
10704 "%10d %"Z"x -\n" : "%10d %"Z"x %"Y"u\n",
10705 (int)mr[i].mr_pid, (size_t)mr[i].mr_tid, txnid);
10708 rc = func(" pid thread txnid\n", ctx);
10712 rc = func(buf, ctx);
10718 rc = func("(no active readers)\n", ctx);
10723 /** Insert pid into list if not already present.
10724 * return -1 if already present.
10727 mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)
10729 /* binary search of pid in list */
10731 unsigned cursor = 1;
10733 unsigned n = ids[0];
10736 unsigned pivot = n >> 1;
10737 cursor = base + pivot + 1;
10738 val = pid - ids[cursor];
10743 } else if ( val > 0 ) {
10748 /* found, so it's a duplicate */
10757 for (n = ids[0]; n > cursor; n--)
10764 mdb_reader_check(MDB_env *env, int *dead)
10770 return env->me_txns ? mdb_reader_check0(env, 0, dead) : MDB_SUCCESS;
10773 /** As #mdb_reader_check(). rlocked = <caller locked the reader mutex>. */
10775 mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
10777 mdb_mutexref_t rmutex = rlocked ? NULL : env->me_rmutex;
10778 unsigned int i, j, rdrs;
10780 MDB_PID_T *pids, pid;
10781 int rc = MDB_SUCCESS, count = 0;
10783 rdrs = env->me_txns->mti_numreaders;
10784 pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
10788 mr = env->me_txns->mti_readers;
10789 for (i=0; i<rdrs; i++) {
10790 pid = mr[i].mr_pid;
10791 if (pid && pid != env->me_pid) {
10792 if (mdb_pid_insert(pids, pid) == 0) {
10793 if (!mdb_reader_pid(env, Pidcheck, pid)) {
10794 /* Stale reader found */
10797 if ((rc = LOCK_MUTEX0(rmutex)) != 0) {
10798 if ((rc = mdb_mutex_failed(env, rmutex, rc)))
10800 rdrs = 0; /* the above checked all readers */
10802 /* Recheck, a new process may have reused pid */
10803 if (mdb_reader_pid(env, Pidcheck, pid))
10807 for (; j<rdrs; j++)
10808 if (mr[j].mr_pid == pid) {
10809 DPRINTF(("clear stale reader pid %u txn %"Y"d",
10810 (unsigned) pid, mr[j].mr_txnid));
10815 UNLOCK_MUTEX(rmutex);
10826 #ifdef MDB_ROBUST_SUPPORTED
10827 /** Handle #LOCK_MUTEX0() failure.
10828 * Try to repair the lock file if the mutex owner died.
10829 * @param[in] env the environment handle
10830 * @param[in] mutex LOCK_MUTEX0() mutex
10831 * @param[in] rc LOCK_MUTEX0() error (nonzero)
10832 * @return 0 on success with the mutex locked, or an error code on failure.
10835 mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc)
10840 if (rc == MDB_OWNERDEAD) {
10841 /* We own the mutex. Clean up after dead previous owner. */
10843 rlocked = (mutex == env->me_rmutex);
10845 /* Keep mti_txnid updated, otherwise next writer can
10846 * overwrite data which latest meta page refers to.
10848 meta = mdb_env_pick_meta(env);
10849 env->me_txns->mti_txnid = meta->mm_txnid;
10850 /* env is hosed if the dead thread was ours */
10852 env->me_flags |= MDB_FATAL_ERROR;
10853 env->me_txn = NULL;
10857 DPRINTF(("%cmutex owner died, %s", (rlocked ? 'r' : 'w'),
10858 (rc ? "this process' env is hosed" : "recovering")));
10859 rc2 = mdb_reader_check0(env, rlocked, NULL);
10861 rc2 = mdb_mutex_consistent(mutex);
10862 if (rc || (rc = rc2)) {
10863 DPRINTF(("LOCK_MUTEX recovery failed, %s", mdb_strerror(rc)));
10864 UNLOCK_MUTEX(mutex);
10870 DPRINTF(("LOCK_MUTEX failed, %s", mdb_strerror(rc)));
10875 #endif /* MDB_ROBUST_SUPPORTED */
10878 #if defined(_WIN32)
10879 static int utf8_to_utf16(const char *src, int srcsize, wchar_t **dst, int *dstsize)
10883 need = MultiByteToWideChar(CP_UTF8, 0, src, srcsize, NULL, 0);
10884 if (need == 0xFFFD)
10888 result = malloc(sizeof(wchar_t) * need);
10891 MultiByteToWideChar(CP_UTF8, 0, src, srcsize, result, need);
10897 #endif /* defined(_WIN32) */
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